Diamond is a solid form of carbon with a diamond cubic crystal
structure. At room temperature and pressure it is metastable and
graphite is the stable form, but diamond almost never converts to
Diamond is renowned for its superlative physical qualities,
most of which originate from the strong covalent bonding between its
atoms. In particular, it has the highest hardness and thermal
conductivity of any bulk material. Those properties determine the
major industrial applications of diamond in cutting and polishing
tools and the scientific applications in diamond knives and diamond
Because of its extremely rigid lattice, diamond can be contaminated by
very few types of impurities, such as boron and nitrogen. Small
amounts of defects or impurities (about one per million of lattice
atoms) color diamond blue (boron), yellow (nitrogen), brown (lattice
defects), green (radiation exposure), purple, pink, orange or red.
Diamond also has relatively high optical dispersion (ability to
disperse light of different colors).
Most natural diamonds have ages between 1 billion and
3.5 billion years. Most were formed at depths of 150 to 250
kilometers (93 to 155 mi) in the Earth's mantle, although a few
have come from as deep as 800 kilometers (500 mi). Under high
pressure and temperature, carbon-containing fluids dissolved minerals
and replaced them with diamonds. Much more recently (tens to hundreds
of million years ago), they were carried to the surface in volcanic
eruptions and deposited in igneous rocks known as kimberlites and
Diamonds can be produced synthetically in a high pressure, high
temperature method (HPHT) which approximately simulates the conditions
in the Earth's mantle. An alternative, and completely different growth
technique is chemical vapor deposition (CVD). Several non-diamond
materials, which include cubic zirconia and silicon carbide and are
often called diamond simulants, resemble diamond in appearance and
Special gemological techniques have been developed to
distinguish natural diamonds, synthetic diamonds, and diamond
2.1 Surface distribution
2.4 Origin in mantle
2.6 Formation and growth
2.7 Transport to the surface
2.8 In space
3 Material properties
3.3 Pressure resistance
3.4 Electrical conductivity
3.5 Surface property
3.6 Chemical stability
4.1 Gem-grade diamonds
4.2 Industrial-grade diamonds
4.3.1 Political issues
5 Synthetics, simulants, and enhancements
6 Stolen diamonds
7 See also
10 External links
The name diamond is derived from the ancient Greek αδάμας
(adámas), "proper", "unalterable", "unbreakable", "untamed", from
ἀ- (a-), "un-" + δαμάω (damáō), "I overpower", "I tame".
Diamonds are thought to have been first recognized and mined in India,
where significant alluvial deposits of the stone could be found many
centuries ago along the rivers Penner, Krishna and Godavari. Diamonds
have been known in
India for at least 3,000 years but most likely
Diamonds have been treasured as gemstones since their use as religious
icons in ancient India. Their usage in engraving tools also dates to
early human history. The popularity of diamonds has risen since
the 19th century because of increased supply, improved cutting and
polishing techniques, growth in the world economy, and innovative and
successful advertising campaigns.
In 1772, the French scientist
Antoine Lavoisier used a lens to
concentrate the rays of the sun on a diamond in an atmosphere of
oxygen, and showed that the only product of the combustion was carbon
dioxide, proving that diamond is composed of carbon. Later in 1797,
the English chemist
Smithson Tennant repeated and expanded that
experiment. By demonstrating that burning diamond and graphite
releases the same amount of gas, he established the chemical
equivalence of these substances.
The most familiar uses of diamonds today are as gemstones used for
adornment, and as industrial abrasives for cutting hard materials. The
dispersion of white light into spectral colors is the primary
gemological characteristic of gem diamonds. In the 20th century,
experts in gemology developed methods of grading diamonds and other
gemstones based on the characteristics most important to their value
as a gem. Four characteristics, known informally as the four Cs, are
now commonly used as the basic descriptors of diamonds: these are
carat (its weight), cut (quality of the cut is graded according to
proportions, symmetry and polish), color (how close to white or
colorless; for fancy diamonds how intense is its hue), and clarity
(how free is it from inclusions). A large, flawless diamond is
known as a paragon.
Diamonds are extremely rare, with concentrations of at most parts per
billion in source rock. Before the 20th century, most diamonds
were found in alluvial deposits. Loose diamonds are also found along
existing and ancient shorelines, where they tend to accumulate because
of their size and density.:149 Rarely, they have been found in
glacial till (notably in
Wisconsin and Indiana), but these deposits
are not of commercial quality.:19 These types of deposit were
derived from localized igneous intrusions through weathering and
transport by wind or water.
Most diamonds come from the Earth's mantle, and most of this section
discusses those diamonds. However, there are other sources. Some
blocks of the crust, or terranes, have been buried deep enough as the
crust thickened so they experienced ultra-high-pressure metamorphism.
These have evenly distributed microdiamonds that show no sign of
transport by magma. In addition, when meteorites strike the ground,
the shock wave can produce high enough temperatures and pressures for
microdiamonds and nanodiamonds to form. Impact-type microdiamonds
can be used as an indicator of ancient impact craters. Popigai
Russia may have the world's largest diamond deposit,
estimated at trillions of carats, and formed by an asteroid
A common misconception is that diamonds are formed from highly
Coal is formed from buried prehistoric plants, and
most diamonds that have been dated are far older than the first land
plants. It is possible that diamonds can form from coal in subduction
zones, but diamonds formed in this way are rare, and the carbon source
is more likely carbonate rocks and organic carbon in sediments, rather
Geologic provinces of the world. The pink and orange areas are shields
and platforms, which together constitute cratons.
Diamonds are far from evenly distributed over the Earth. A rule of
thumb known as Clifford's rule states that they are almost always
found in kimberlites on the oldest part of cratons, the stable cores
of continents with typical ages of 2.5 billion years or
more.:314 However, there are exceptions. The Argyle diamond
mine in Australia, the largest producer of diamonds by weight in the
world, is located in a mobile belt, also known as an orogenic
belt, a weaker zone surrounding the central craton that has
undergone compressional tectonics. Instead of kimberlite, the host
rock is lamproite. Lamproites with diamonds that are not economically
viable are also found in the United States,
India and Australia.
In addition, diamonds in the Wawa belt of the Superior province in
Canada and microdiamonds in the island arc of Japan are found in a
type of rock called lamprophyre.
Kimberlites can be found in narrow (1–4 meters) dikes and sills, and
in pipes with diameters that range from about 75 meters to 1.5
kilometers. Fresh rock is dark bluish green to greenish gray, but
after exposure rapidly turns brown and crumbles. It is hybrid rock
with a chaotic mixture of small minerals and rock fragments (clasts)
up to the size of watermelons. They are a mixture of xenocrysts and
xenoliths (minerals and rocks carried up from the lower crust and
mantle), pieces of surface rock, altered minerals such as serpentine,
and new minerals that crystallized during the eruption. The texture
varies with depth. The composition forms a continuum with
carbonatites, but the latter have too much oxygen for carbon to exist
in a pure form. Instead, it is locked up in the mineral calcite
All three of the diamond-bearing rocks (kimberlite, lamproite and
lamprophyre) lack certain minerals (melilite and kalsilite) that are
incompatible with diamond formation. In kimberlite, olivine is large
and conspicuous, while lamproite has Ti-phlogopite and lamprophyre has
biotite and amphibole. They are all derived from magma types that
erupt rapidly from small amounts of melt, are rich in volatiles and
magnesium oxide, and are less oxidizing than more common mantle melts
such as basalt. These characteristics allow the melts to carry
diamonds to the surface before they dissolve.
Diavik Mine, on an island in Lac de Gras in northern Canada.
Kimberlite pipes can be difficult to find. They weather quickly
(within a few years after exposure) and tend to have lower topographic
relief than surrounding rock. If they are visible in outcrops, the
diamonds are never visible because they are so rare. In any case,
kimberlites are often covered with vegetation, sediments, soils or
lakes. In modern searches, geophysical methods such as aeromagnetic
surveys, electrical resistivity and gravimetry, help identify
promising regions to explore. This is aided by isotopic dating and
modeling of the geological history. Then surveyors must go to the area
and collect samples, looking for kimberlite fragments or indicator
minerals. The latter have compositions that reflect the conditions
where diamonds form, such as extreme melt depletion or high pressures
in eclogites. However, indicator minerals can be misleading; a better
approach is geothermobarometry, where the compositions of minerals are
analyzed as if they were in equilibrium with mantle minerals.
Finding kimberlites requires persistence, and only a small fraction
contain diamonds that are commercially viable. The only major
discoveries since about 1980 have been in Canada. Since existing mines
have lifetimes of as little as 25 years, there could be a shortage of
new diamonds in the future.
Diamonds are dated by analyzing inclusions using the decay of
radioactive isotopes. Depending on the elemental abundances, one can
look at the decay of rubidium to strontium, samarium to neodymium,
uranium to lead, argon-40 to argon-39, or rhenium to osmium. Those
found in kimberlites have ages ranging from 1 to 3.5 billion years,
and there can be multiple ages in the same kimberlite, indicating
multiple episodes of diamond formation. The kimberlites themselves are
much younger. Most of them have ages between tens of millions and 300
million years old, although there are some older exceptions (Argyle,
Premier and Wawa). Thus, the kimberlites formed independently of the
diamonds and served only to transport them to the surface.
Kimberlites are also much younger than the cratons they have erupted
through. The reason for the lack of older kimberlites is unknown, but
it suggests there was some change in mantle chemistry or tectonics. No
kimberlite has erupted in human history.
Origin in mantle
Eclogite with centimeter-size garnet crystals.
Most gem-quality diamonds come from depths of 150 to 250 kilometers in
the lithosphere. Such depths occur below cratons in mantle keels, the
thickest part of the lithosphere. These regions have high enough
pressure and temperature to allow diamonds to form and they are not
convecting, so diamonds can be stored for billions of years until a
kimberlite eruption samples them.
Host rocks in a mantle keel include harzburgite and lherzolite, two
type of peridotite. The most dominant rock type in the upper mantle,
peridotite is an igneous rock consisting mostly of the minerals
olivine and pyroxene; it is low in silica and high in magnesium.
However, diamonds in peridotite rarely survive the trip to the
surface. Another common source that does keep diamonds intact is
eclogite, a metamorphic rock that typically forms from basalt as an
oceanic plate plunges into the mantle at a subduction zone.
A smaller fraction of diamonds (about 150 have been studied) come from
depths of 330–660 kilometers, a region that includes the transition
zone. They formed in eclogite but are distinguished from diamonds of
shallower origin by inclusions of majorite (a form of garnet with
excess silicon). A similar proportion of diamonds comes from the lower
mantle at depths between 660 and 800 kilometers.
Diamond is thermodynamically stable at high pressures and
temperatures, with the phase transition from graphite occurring at
greater temperatures as the pressure increases. Thus, underneath
continents it becomes stable at temperatures of 950 degrees Celsius
and pressures of 4.5 gigapascals, corresponding to depths of 150
kilometers or greater. In subduction zones, which are colder, it
becomes stable at temperatures of 800 degrees C and pressures of 3.5
gigapascals. At depths greater than 240 km, iron-nickel metal phases
are present and carbon is likely to be either dissolved in them or in
the form of carbides. Thus, the deeper origin of some diamonds may
reflect unusual growth environments.
The amount of carbon in the mantle is not well constrained, but its
concentration is estimated at 0.5 to 1 parts per thousand. It has
two stable isotopes, 12C and 13C, in a ratio of approximately 99:1 by
mass. This ratio has a wide range in meteorites, which implies that it
was probably also broad in the early Earth. It can also be altered by
surface processes like photosynthesis. The fraction is generally
compared to a standard sample using a ratio δ13C expressed in parts
per thousand. Common rocks from the mantle such as basalts,
carbonatites and kimberlites have ratios between -8 and -2. On the
surface, organic sediments have an average of -25 while carbonates
have an average of 0.
Populations of diamonds from different sources have distributions of
δ13C that vary markedly. Peridotitic diamonds are mostly within the
typical mantle range; eclogitic diamonds have values from -40 to +3,
although the peak of the distribution is in the mantle range. This
variability implies that they are not formed from carbon that is
primordial (having resided in the mantle since the
Instead, they are the result of tectonic processes, although (given
the ages of diamonds) not necessarily the same tectonic processes that
act in the present.
Formation and growth
Diamonds in the mantle form through a metasomatic process where a
C-O-H-N-S fluid or melt dissolves minerals in a rock and replaces them
with new minerals. (The vague term C-O-H-N-S is commonly used because
the exact composition is not known.) Diamonds form from this fluid
either by reduction of oxidized carbon (e.g., CO2 or CO3) or oxidation
of a reduced phase such as methane.
Using probes such as polarized light, photoluminescence and
cathodoluminescence, a series of growth zones can be identified in
diamonds. The characteristic pattern in diamonds from the lithosphere
involves a nearly concentric series of zones with very thin
oscillations in luminescence and alternating episodes where the carbon
is resorbed by the fluid and then grown again. Diamonds from below the
lithosphere have a more irregular, almost polycrystalline texture,
reflecting the higher temperatures and pressures as well as the
transport of the diamonds by convection.
Transport to the surface
Diagram of a volcanic pipe
Geological evidence supports a model in which kimberlite magma rose at
4–20 meters per second, creating an upward path by hydraulic
fracturing of the rock. As the pressure decreases, a vapor phase
exsolves from the magma, and this helps to keep the magma fluid. At
the surface, the initial eruption explodes out through fissures at
high speeds (over 200 meters per second). Then, at lower pressures,
the rock is eroded, forming a pipe and producing fragmented rock
(breccia). As the eruption wanes, there is pyroclastic phase and then
metamorphism and hydration produces serpentinites.
Main article: Extraterrestrial diamonds
Although diamonds on
Earth are rare, they are very common in space. In
meteorites, about 3 percent of the carbon is in the form of
nanodiamonds, having diameters of a few nanometers. Sufficiently small
diamonds can form in the cold of space because their lower surface
energy makes them more stable than graphite. The isotopic signatures
of some nanodiamonds indicate they were formed outside the Solar
System in stars.
High pressure experiments predict that large quantities of diamonds
condense from methane into a "diamond rain" on the ice giant planets
Uranus and Neptune. Some extrasolar planets may be almost
entirely composed of diamond.
Diamonds may exist in carbon-rich stars, particularly white dwarfs.
One theory for the origin of carbonado, the toughest form of diamond,
is that it originated in a white dwarf or supernova. Diamonds
formed in stars may have been the first minerals.
Material properties of diamond
Material properties of diamond and Crystallographic
defects in diamond
Theoretically predicted phase diagram of carbon
Diamond and graphite are two allotropes of carbon (pure forms of the
same element that differ in structure).
A diamond is a transparent crystal of tetrahedrally bonded carbon
atoms in a covalent network lattice (sp3) that crystallizes into the
diamond lattice which is a variation of the face-centered cubic
structure. Diamonds have been adapted for many uses because of the
material's exceptional physical characteristics. Most notable are its
extreme hardness and thermal conductivity
(900–7003232000000000000♠2320 W·m−1·K−1), as well
as wide bandgap and high optical dispersion. Above
7003197315000000000♠1700 °C (7003197300000000000♠1973 K
/ 7003224592777777777♠3583 °F) in vacuum or oxygen-free
atmosphere, diamond converts to graphite; in air, transformation
starts at ~7002973150000000000♠700 °C. Diamond's ignition
point is 720–7003107315000000000♠800 °C in oxygen and
850–7003127315000000000♠1000 °C in air. Naturally occurring
diamonds have a density ranging from 3.15 to
7003353000000000000♠3.53 g/cm3, with pure diamond close to
7003352000000000000♠3.52 g/cm3. The chemical bonds that hold
the carbon atoms in diamonds together are weaker than those in
graphite. In diamonds, the bonds form an inflexible three-dimensional
lattice, whereas in graphite, the atoms are tightly bonded into
sheets, which can slide easily over one another, making the overall
structure weaker. In a diamond, each carbon atom is surrounded by
neighboring four carbon atoms forming a tetrahedral shaped unit.
One face of an uncut octahedral diamond, showing trigons (of positive
and negative relief) formed by natural chemical etching
Diamonds occur most often as euhedral or rounded octahedra and twinned
octahedra known as macles. As diamond's crystal structure has a cubic
arrangement of the atoms, they have many facets that belong to a cube,
octahedron, rhombicosidodecahedron, tetrakis hexahedron or disdyakis
dodecahedron. The crystals can have rounded off and unexpressive edges
and can be elongated. Diamonds (especially those with rounded crystal
faces) are commonly found coated in nyf, an opaque gum-like skin.
Some diamonds have opaque fibers. They are referred to as opaque if
the fibers grow from a clear substrate or fibrous if they occupy the
entire crystal. Their colors range from yellow to green or gray,
sometimes with cloud-like white to gray impurities. Their most common
shape is cuboidal, but they can also form octahedra, dodecahedra,
macles or combined shapes. The structure is the result of numerous
impurities with sizes between 1 and 5 microns. These diamonds probably
formed in kimberlite magma and sampled the volatiles.
Diamonds can also form polycrystalline aggregates. There have been
attempts to classify them into groups with names such as boart,
ballas, stewartite and framesite, but there is no widely accepted set
of criteria. Carbonado, a type in which the diamond grains were
sintered (fused without melting by the application of heat and
pressure), is black in color and tougher than single crystal
diamond. It has never been observed in a volcanic rock. There are
many theories for its origin, including formation in a star, but no
Diamond is the hardest known natural material on both the Vickers
scale and the Mohs scale. Diamond's great hardness relative to other
materials has been known since antiquity, and is the source of its
Diamond hardness depends on its purity, crystalline perfection and
orientation: hardness is higher for flawless, pure crystals oriented
to the <111> direction (along the longest diagonal of the cubic
diamond lattice). Therefore, whereas it might be possible to
scratch some diamonds with other materials, such as boron nitride, the
hardest diamonds can only be scratched by other diamonds and
nanocrystalline diamond aggregates.
The hardness of diamond contributes to its suitability as a gemstone.
Because it can only be scratched by other diamonds, it maintains its
polish extremely well. Unlike many other gems, it is well-suited to
daily wear because of its resistance to scratching—perhaps
contributing to its popularity as the preferred gem in engagement or
wedding rings, which are often worn every day.
The extreme hardness of diamond in certain orientations makes it
useful in materials science, as in this pyramidal diamond embedded in
the working surface of a Vickers hardness tester.
The hardest natural diamonds mostly originate from the Copeton and
Bingara fields located in the New England area in New South Wales,
Australia. These diamonds are generally small, perfect to semiperfect
octahedra, and are used to polish other diamonds. Their hardness is
associated with the crystal growth form, which is single-stage crystal
growth. Most other diamonds show more evidence of multiple growth
stages, which produce inclusions, flaws, and defect planes in the
crystal lattice, all of which affect their hardness. It is possible to
treat regular diamonds under a combination of high pressure and high
temperature to produce diamonds that are harder than the diamonds used
in hardness gauges.
Somewhat related to hardness is another mechanical property toughness,
which is a material's ability to resist breakage from forceful impact.
The toughness of natural diamond has been measured as 7.5–10
MPa·m1/2. This value is good compared to other ceramic
materials, but poor compared to most engineering materials such as
engineering alloys, which typically exhibit toughnesses over 100
MPa·m1/2. As with any material, the macroscopic geometry of a diamond
contributes to its resistance to breakage.
Diamond has a cleavage
plane and is therefore more fragile in some orientations than others.
Diamond cutters use this attribute to cleave some stones, prior to
faceting. "Impact toughness" is one of the main indexes to measure
the quality of synthetic industrial diamonds.
Used in so-called diamond anvil experiments to create high-pressure
environments, diamonds are able to withstand crushing pressures in
excess of 600 gigapascals (6 million atmospheres).
Other specialized applications also exist or are being developed,
including use as semiconductors: some blue diamonds are natural
semiconductors, in contrast to most diamonds, which are excellent
electrical insulators. The conductivity and blue color originate
from boron impurity.
Boron substitutes for carbon atoms in the diamond
lattice, donating a hole into the valence band.
Substantial conductivity is commonly observed in nominally undoped
diamond grown by chemical vapor deposition. This conductivity is
associated with hydrogen-related species adsorbed at the surface, and
it can be removed by annealing or other surface treatments.
Diamonds are naturally lipophilic and hydrophobic, which means the
diamonds' surface cannot be wet by water, but can be easily wet and
stuck by oil. This property can be utilized to extract diamonds using
oil when making synthetic diamonds. However, when diamond surfaces are
chemically modified with certain ions, they are expected to become so
hydrophilic that they can stabilize multiple layers of water ice at
human body temperature.
The surface of diamonds is partially oxidized. The oxidized surface
can be reduced by heat treatment under hydrogen flow. That is to say,
this heat treatment partially removes oxygen-containing functional
groups. But diamonds (sp3C) are unstable against high temperature
(above about 400 °C (752 °F)) under atmospheric pressure.
The structure gradually changes into sp2C above this temperature.
Thus, diamonds should be reduced under this temperature.
Diamonds are not very reactive. Under room temperature diamonds do not
react with any chemical reagents including strong acids and bases. A
diamond's surface can only be oxidized at temperatures above about
850 °C (1,560 °F) in air.
Diamond also reacts with
fluorine gas above about 700 °C (1,292 °F).
Brown diamonds at the
National Museum of Natural History
National Museum of Natural History in
The most famous colored diamond, the Hope Diamond
Diamond has a wide bandgap of 6981881197067849999♠5.5 eV
corresponding to the deep ultraviolet wavelength of 225 nanometers.
This means that pure diamond should transmit visible light and appear
as a clear colorless crystal. Colors in diamond originate from lattice
defects and impurities. The diamond crystal lattice is exceptionally
strong, and only atoms of nitrogen, boron and hydrogen can be
introduced into diamond during the growth at significant
concentrations (up to atomic percents). Transition metals nickel and
cobalt, which are commonly used for growth of synthetic diamond by
high-pressure high-temperature techniques, have been detected in
diamond as individual atoms; the maximum concentration is 0.01% for
nickel and even less for cobalt. Virtually any element can be
introduced to diamond by ion implantation.
Nitrogen is by far the most common impurity found in gem diamonds and
is responsible for the yellow and brown color in diamonds.
responsible for the blue color. Color in diamond has two
additional sources: irradiation (usually by alpha particles), that
causes the color in green diamonds, and plastic deformation of the
diamond crystal lattice.
Plastic deformation is the cause of color in
some brown and perhaps pink and red diamonds. In order of
increasing rarity, yellow diamond is followed by brown, colorless,
then by blue, green, black, pink, orange, purple, and red.
"Black", or Carbonado, diamonds are not truly black, but rather
contain numerous dark inclusions that give the gems their dark
appearance. Colored diamonds contain impurities or structural defects
that cause the coloration, while pure or nearly pure diamonds are
transparent and colorless. Most diamond impurities replace a carbon
atom in the crystal lattice, known as a carbon flaw. The most common
impurity, nitrogen, causes a slight to intense yellow coloration
depending upon the type and concentration of nitrogen present. The
Gemological Institute of America (GIA) classifies low saturation
yellow and brown diamonds as diamonds in the normal color range, and
applies a grading scale from "D" (colorless) to "Z" (light yellow).
Diamonds of a different color, such as blue, are called fancy colored
diamonds and fall under a different grading scale.
In 2008, the Wittelsbach Diamond, a 35.56-carat (7.112 g) blue
diamond once belonging to the King of Spain, fetched over
US$24 million at a Christie's auction. In May 2009, a
7.03-carat (1.406 g) blue diamond fetched the highest price per
carat ever paid for a diamond when it was sold at auction for
10.5 million Swiss francs (6.97 million euros, or
US$9.5 million at the time). That record was, however, beaten
the same year: a 5-carat (1.0 g) vivid pink diamond was sold for
$10.8 million in Hong Kong on December 1, 2009.
Diamonds can be identified by their high thermal conductivity. Their
high refractive index is also indicative, but other materials have
similar refractivity. Diamonds cut glass, but this does not positively
identify a diamond because other materials, such as quartz, also lie
above glass on the
Mohs scale and can also cut it. Diamonds can
scratch other diamonds, but this can result in damage to one or both
stones. Hardness tests are infrequently used in practical gemology
because of their potentially destructive nature. The extreme
hardness and high value of diamond means that gems are typically
polished slowly, using painstaking traditional techniques and greater
attention to detail than is the case with most other gemstones;
these tend to result in extremely flat, highly polished facets with
exceptionally sharp facet edges. Diamonds also possess an extremely
high refractive index and fairly high dispersion. Taken together,
these factors affect the overall appearance of a polished diamond and
most diamantaires still rely upon skilled use of a loupe (magnifying
glass) to identify diamonds "by eye".
A round brilliant cut diamond set in a ring
Diamonds as an investment
Diamonds as an investment and Clean
Diamond Trade Act
The diamond industry can be separated into two distinct categories:
one dealing with gem-grade diamonds and another for industrial-grade
diamonds. Both markets value diamonds differently.
Diamond exports by country (2014) from Harvard Atlas of Economic
A large trade in gem-grade diamonds exists. Although most gem-grade
diamonds are sold newly polished, there is a well-established market
for resale of polished diamonds (e.g. pawnbroking, auctions,
second-hand jewelry stores, diamantaires, bourses, etc.). One hallmark
of the trade in gem-quality diamonds is its remarkable concentration:
wholesale trade and diamond cutting is limited to just a few
locations; in 2003, 92% of the world's diamonds were cut and polished
in Surat, India. Other important centers of diamond cutting and
trading are the
Antwerp diamond district
Antwerp diamond district in Belgium, where the
International Gemological Institute is based, London, the Diamond
District in New York City, the
Diamond Exchange District
Diamond Exchange District in Tel Aviv,
and Amsterdam. One contributory factor is the geological nature of
diamond deposits: several large primary kimberlite-pipe mines each
account for significant portions of market share (such as the Jwaneng
mine in Botswana, which is a single large-pit mine that can produce
between 12,500,000 and 15,000,000 carats (2,500 and 3,000 kg) of
diamonds per year). Secondary alluvial diamond deposits, on the
other hand, tend to be fragmented amongst many different operators
because they can be dispersed over many hundreds of square kilometers
(e.g., alluvial deposits in Brazil).
The production and distribution of diamonds is largely consolidated in
the hands of a few key players, and concentrated in traditional
diamond trading centers, the most important being Antwerp, where 80%
of all rough diamonds, 50% of all cut diamonds and more than 50% of
all rough, cut and industrial diamonds combined are handled. This
makes Antwerp a de facto "world diamond capital". The city of
Antwerp also hosts the Antwerpsche Diamantkring, created in 1929 to
become the first and biggest diamond bourse dedicated to rough
diamonds. Another important diamond center is New York City, where
almost 80% of the world's diamonds are sold, including auction
De Beers company, as the world's largest diamond mining company,
holds a dominant position in the industry, and has done so since soon
after its founding in 1888 by the British imperialist Cecil Rhodes. De
Beers is currently the world's largest operator of diamond production
facilities (mines) and distribution channels for gem-quality diamonds.
Diamond Trading Company (DTC) is a subsidiary of
De Beers and
markets rough diamonds from De Beers-operated mines.
De Beers and its
subsidiaries own mines that produce some 40% of annual world diamond
production. For most of the 20th century over 80% of the world's rough
diamonds passed through De Beers, but by 2001–2009 the figure
had decreased to around 45%, and by 2013 the company's market
share had further decreased to around 38% in value terms and even less
De Beers sold off the vast majority of its diamond
stockpile in the late 1990s – early 2000s and the remainder
largely represents working stock (diamonds that are being sorted
before sale). This was well documented in the press but
remains little known to the general public.
As a part of reducing its influence,
De Beers withdrew from purchasing
diamonds on the open market in 1999 and ceased, at the end of 2008,
purchasing Russian diamonds mined by the largest Russian diamond
company Alrosa. As of January 2011,
De Beers states that it only
sells diamonds from the following four countries: Botswana, Namibia,
South Africa and Canada.
Alrosa had to suspend their sales in
October 2008 due to the global energy crisis, but the company
reported that it had resumed selling rough diamonds on the open market
by October 2009. Apart from Alrosa, other important diamond mining
companies include BHP Billiton, which is the world's largest mining
company; Rio Tinto Group, the owner of the Argyle (100%), Diavik
(60%), and Murowa (78%) diamond mines; and Petra Diamonds, the
owner of several major diamond mines in Africa.
Diamond polisher in Amsterdam
Further down the supply chain, members of The World Federation of
Diamond Bourses (WFDB) act as a medium for wholesale diamond exchange,
trading both polished and rough diamonds. The WFDB consists of
independent diamond bourses in major cutting centers such as Tel Aviv,
Antwerp, Johannesburg and other cities across the USA, Europe and
Asia. In 2000, the WFDB and The International Diamond
Manufacturers Association established the
World Diamond Council to
prevent the trading of diamonds used to fund war and inhumane acts.
WFDB's additional activities include sponsoring the World Diamond
Congress every two years, as well as the establishment of the
International Diamond Council (IDC) to oversee diamond grading.
Once purchased by Sightholders (which is a trademark term referring to
the companies that have a three-year supply contract with DTC),
diamonds are cut and polished in preparation for sale as gemstones
('industrial' stones are regarded as a by-product of the gemstone
market; they are used for abrasives). The cutting and polishing of
rough diamonds is a specialized skill that is concentrated in a
limited number of locations worldwide. Traditional diamond cutting
centers are Antwerp, Amsterdam, Johannesburg, New York City, and Tel
Aviv. Recently, diamond cutting centers have been established in
China, India, Thailand, Namibia and Botswana. Cutting centers with
lower cost of labor, notably
Surat in Gujarat, India, handle a larger
number of smaller carat diamonds, while smaller quantities of larger
or more valuable diamonds are more likely to be handled in Europe or
North America. The recent expansion of this industry in India,
employing low cost labor, has allowed smaller diamonds to be prepared
as gems in greater quantities than was previously economically
Diamonds prepared as gemstones are sold on diamond exchanges called
bourses. There are 28 registered diamond bourses in the world.
Bourses are the final tightly controlled step in the diamond supply
chain; wholesalers and even retailers are able to buy relatively small
lots of diamonds at the bourses, after which they are prepared for
final sale to the consumer. Diamonds can be sold already set in
jewelry, or sold unset ("loose"). According to the Rio Tinto Group, in
2002 the diamonds produced and released to the market were valued at
US$9 billion as rough diamonds, US$14 billion after being
cut and polished, US$28 billion in wholesale diamond jewelry, and
US$57 billion in retail sales.
Diamond cutting and
The Darya-I-Nur Diamond—an example of unusual diamond cut and
Mined rough diamonds are converted into gems through a multi-step
process called "cutting". Diamonds are extremely hard, but also
brittle and can be split up by a single blow. Therefore, diamond
cutting is traditionally considered as a delicate procedure requiring
skills, scientific knowledge, tools and experience. Its final goal is
to produce a faceted jewel where the specific angles between the
facets would optimize the diamond luster, that is dispersion of white
light, whereas the number and area of facets would determine the
weight of the final product. The weight reduction upon cutting is
significant and can be of the order of 50%. Several possible
shapes are considered, but the final decision is often determined not
only by scientific, but also practical considerations. For example,
the diamond might be intended for display or for wear, in a ring or a
necklace, singled or surrounded by other gems of certain color and
shape. Some of them may be considered as classical, such as round,
pear, marquise, oval, hearts and arrows diamonds, etc. Some of them
are special, produced by certain companies, for example, Phoenix,
Cushion, Sole Mio diamonds, etc.
The most time-consuming part of the cutting is the preliminary
analysis of the rough stone. It needs to address a large number of
issues, bears much responsibility, and therefore can last years in
case of unique diamonds. The following issues are considered:
The hardness of diamond and its ability to cleave strongly depend on
the crystal orientation. Therefore, the crystallographic structure of
the diamond to be cut is analyzed using
X-ray diffraction to choose
the optimal cutting directions.
Most diamonds contain visible non-diamond inclusions and crystal
flaws. The cutter has to decide which flaws are to be removed by the
cutting and which could be kept.
The diamond can be split by a single, well calculated blow of a hammer
to a pointed tool, which is quick, but risky. Alternatively, it can be
cut with a diamond saw, which is a more reliable but tedious
After initial cutting, the diamond is shaped in numerous stages of
polishing. Unlike cutting, which is a responsible but quick operation,
polishing removes material by gradual erosion and is extremely time
consuming. The associated technique is well developed; it is
considered as a routine and can be performed by technicians. After
polishing, the diamond is reexamined for possible flaws, either
remaining or induced by the process. Those flaws are concealed through
various diamond enhancement techniques, such as repolishing, crack
filling, or clever arrangement of the stone in the jewelry. Remaining
non-diamond inclusions are removed through laser drilling and filling
of the voids produced.
Diamond Balance Scale 0.01 - 25 Carats Jewelers Measuring Tool
Marketing has significantly affected the image of diamond as a
N. W. Ayer & Son, the advertising firm retained by
De Beers in the
mid-20th century, succeeded in reviving the American diamond market.
And the firm created new markets in countries where no diamond
tradition had existed before. N. W. Ayer's marketing included product
placement, advertising focused on the diamond product itself rather
De Beers brand, and associations with celebrities and
royalty. Without advertising the
De Beers brand,
De Beers was
advertising its competitors' diamond products as well, but this
was not a concern as
De Beers dominated the diamond market throughout
the 20th century. De Beers' market share dipped temporarily to 2nd
place in the global market below
Alrosa in the aftermath of the global
economic crisis of 2008, down to less than 29% in terms of carats
mined, rather than sold. The campaign lasted for decades but was
effectively discontinued by early 2011.
De Beers still advertises
diamonds, but the advertising now mostly promotes its own brands, or
licensed product lines, rather than completely "generic" diamond
products. The campaign was perhaps best captured by the slogan "a
diamond is forever". This slogan is now being used by De Beers
Diamond Jewelers, a jewelry firm which is a 50%/50% joint venture
De Beers mining company and LVMH, the luxury goods
Brown-colored diamonds constituted a significant part of the diamond
production, and were predominantly used for industrial purposes. They
were seen as worthless for jewelry (not even being assessed on the
diamond color scale). After the development of
Argyle diamond mine
Argyle diamond mine in
Australia in 1986, and marketing, brown diamonds have become
acceptable gems. The change was mostly due to the numbers: the
Argyle mine, with its 35,000,000 carats (7,000 kg) of diamonds
per year, makes about one-third of global production of natural
diamonds; 80% of Argyle diamonds are brown.
A scalpel with synthetic diamond blade
Close-up photograph of an angle grinder blade with tiny diamonds shown
embedded in the metal
A diamond knife blade used for cutting ultrathin sections (typically
70 to 350 nm) for transmission electron microscopy.
Industrial diamonds are valued mostly for their hardness and thermal
conductivity, making many of the gemological characteristics of
diamonds, such as the 4 Cs, irrelevant for most applications. 80% of
mined diamonds (equal to about 135,000,000 carats (27,000 kg)
annually) are unsuitable for use as gemstones and are used
industrially. In addition to mined diamonds, synthetic diamonds
found industrial applications almost immediately after their invention
in the 1950s; another 570,000,000 carats (114,000 kg) of
synthetic diamond is produced annually for industrial use (in 2004; in
2014 it is 4,500,000,000 carats (900,000 kg), 90% of which is
produced in China). Approximately 90% of diamond grinding grit is
currently of synthetic origin.
The boundary between gem-quality diamonds and industrial diamonds is
poorly defined and partly depends on market conditions (for example,
if demand for polished diamonds is high, some lower-grade stones will
be polished into low-quality or small gemstones rather than being sold
for industrial use). Within the category of industrial diamonds, there
is a sub-category comprising the lowest-quality, mostly opaque stones,
which are known as bort.
Industrial use of diamonds has historically been associated with their
hardness, which makes diamond the ideal material for cutting and
grinding tools. As the hardest known naturally occurring material,
diamond can be used to polish, cut, or wear away any material,
including other diamonds. Common industrial applications of this
property include diamond-tipped drill bits and saws, and the use of
diamond powder as an abrasive. Less expensive industrial-grade
diamonds, known as bort, with more flaws and poorer color than gems,
are used for such purposes.
Diamond is not suitable for machining
ferrous alloys at high speeds, as carbon is soluble in iron at the
high temperatures created by high-speed machining, leading to greatly
increased wear on diamond tools compared to alternatives.
Specialized applications include use in laboratories as containment
for high-pressure experiments (see diamond anvil cell),
high-performance bearings, and limited use in specialized windows.
With the continuing advances being made in the production of synthetic
diamonds, future applications are becoming feasible. The high thermal
conductivity of diamond makes it suitable as a heat sink for
integrated circuits in electronics.
List of diamond mines
List of diamond mines and Exploration diamond drilling
Approximately 130,000,000 carats (26,000 kg) of diamonds are
mined annually, with a total value of nearly US$9 billion, and
about 100,000 kg (220,000 lb) are synthesized annually.
Roughly 49% of diamonds originate from Central and Southern Africa,
although significant sources of the mineral have been discovered in
Canada, India, Russia, Brazil, and Australia. They are mined from
kimberlite and lamproite volcanic pipes, which can bring diamond
crystals, originating from deep within the
Earth where high pressures
and temperatures enable them to form, to the surface. The mining and
distribution of natural diamonds are subjects of frequent controversy
such as concerns over the sale of blood diamonds or conflict diamonds
by African paramilitary groups. The diamond supply chain is
controlled by a limited number of powerful businesses, and is also
highly concentrated in a small number of locations around the world.
Only a very small fraction of the diamond ore consists of actual
diamonds. The ore is crushed, during which care is required not to
destroy larger diamonds, and then sorted by density. Today, diamonds
are located in the diamond-rich density fraction with the help of
X-ray fluorescence, after which the final sorting steps are done by
hand. Before the use of X-rays became commonplace, the separation
was done with grease belts; diamonds have a stronger tendency to stick
to grease than the other minerals in the ore.
Siberia's Udachnaya diamond mine
Historically, diamonds were found only in alluvial deposits in Guntur
Krishna district of the
Krishna River delta in Southern India.
India led the world in diamond production from the time of their
discovery in approximately the 9th century BC to the mid-18th
century AD, but the commercial potential of these sources had been
exhausted by the late 18th century and at that time
India was eclipsed
Brazil where the first non-Indian diamonds were found in 1725.
Currently, one of the most prominent Indian mines is located at
Diamond extraction from primary deposits (kimberlites and lamproites)
started in the 1870s after the discovery of the
Diamond Fields in
South Africa. Production has increased over time and now an
accumulated total of 4,500,000,000 carats (900,000 kg) have been
mined since that date. Twenty percent of that amount has been
mined in the last five years, and during the last 10 years, nine new
mines have started production; four more are waiting to be opened
soon. Most of these mines are located in Canada, Zimbabwe, Angola, and
one in Russia.
In the U.S., diamonds have been found in Arkansas, Colorado, New
Mexico, Wyoming, and Montana. In 2004, the discovery of a
microscopic diamond in the U.S. led to the January 2008 bulk-sampling
of kimberlite pipes in a remote part of Montana. The Crater of
Diamonds State Park in
Arkansas is open to the public, and is the only
mine in the world where members of the public can dig for
Today, most commercially viable diamond deposits are in
in Sakha Republic, for example Mir pipe and Udachnaya pipe), Botswana,
Australia (Northern and Western Australia) and the Democratic Republic
of the Congo. In 2005,
Russia produced almost one-fifth of the
global diamond output, according to the British Geological Survey.
Australia boasts the richest diamantiferous pipe, with production from
Argyle diamond mine
Argyle diamond mine reaching peak levels of 42 metric tons per
year in the 1990s. There are also commercial deposits being
actively mined in the
Northwest Territories of
Canada and Brazil.
Diamond prospectors continue to search the globe for diamond-bearing
kimberlite and lamproite pipes.
Unsustainable diamond mining in Sierra Leone
Main articles: Kimberley Process, Blood diamond, and Child labour in
the diamond industry
In some of the more politically unstable central African and west
African countries, revolutionary groups have taken control of diamond
mines, using proceeds from diamond sales to finance their operations.
Diamonds sold through this process are known as conflict diamonds or
In response to public concerns that their diamond purchases were
contributing to war and human rights abuses in central and western
Africa, the United Nations, the diamond industry and diamond-trading
nations introduced the
Kimberley Process in 2002. The Kimberley
Process aims to ensure that conflict diamonds do not become intermixed
with the diamonds not controlled by such rebel groups. This is done by
requiring diamond-producing countries to provide proof that the money
they make from selling the diamonds is not used to fund criminal or
revolutionary activities. Although the
Kimberley Process has been
moderately successful in limiting the number of conflict diamonds
entering the market, some still find their way in. According to the
Diamond Manufacturers Association, conflict diamonds
constitute 2–3% of all diamonds traded. Two major flaws still
hinder the effectiveness of the Kimberley Process: (1) the relative
ease of smuggling diamonds across African borders, and (2) the violent
nature of diamond mining in nations that are not in a technical state
of war and whose diamonds are therefore considered "clean".
The Canadian Government has set up a body known as the Canadian
Diamond Code of Conduct to help authenticate Canadian diamonds.
This is a stringent tracking system of diamonds and helps protect the
"conflict free" label of Canadian diamonds.
Synthetics, simulants, and enhancements
Main article: Synthetic diamond
Synthetic diamonds of various colors grown by the high-pressure
Synthetic diamonds are diamonds manufactured in a laboratory, as
opposed to diamonds mined from the Earth. The gemological and
industrial uses of diamond have created a large demand for rough
stones. This demand has been satisfied in large part by synthetic
diamonds, which have been manufactured by various processes for more
than half a century. However, in recent years it has become possible
to produce gem-quality synthetic diamonds of significant size. It
is possible to make colorless synthetic gemstones that, on a molecular
level, are identical to natural stones and so visually similar that
only a gemologist with special equipment can tell the difference.
The majority of commercially available synthetic diamonds are yellow
and are produced by so-called high-pressure high-temperature (HPHT)
processes. The yellow color is caused by nitrogen impurities.
Other colors may also be reproduced such as blue, green or pink, which
are a result of the addition of boron or from irradiation after
Colorless gem cut from diamond grown by chemical vapor deposition
Another popular method of growing synthetic diamond is chemical vapor
deposition (CVD). The growth occurs under low pressure (below
atmospheric pressure). It involves feeding a mixture of gases
(typically 1 to 99 methane to hydrogen) into a chamber and splitting
them to chemically active radicals in a plasma ignited by microwaves,
hot filament, arc discharge, welding torch or laser. This method
is mostly used for coatings, but can also produce single crystals
several millimeters in size (see picture).
As of 2010, nearly all 5,000 million carats (1,000 tonnes) of
synthetic diamonds produced per year are for industrial use. Around
50% of the 133 million carats of natural diamonds mined per year
end up in industrial use. Mining companies' expenses average
$40 to $60 per carat for natural colorless diamonds, while synthetic
manufacturers' expenses average $2,500 per carat for synthetic,
gem-quality colorless diamonds.:79 However, a purchaser is more
likely to encounter a synthetic when looking for a fancy-colored
diamond because nearly all synthetic diamonds are fancy-colored, while
only 0.01% of natural diamonds are.
Gem-cut synthetic silicon carbide set in a ring
A diamond simulant is a non-diamond material that is used to simulate
the appearance of a diamond, and may be referred to as diamante. Cubic
zirconia is the most common. The gemstone moissanite (silicon carbide)
can be treated as a diamond simulant, though more costly to produce
than cubic zirconia. Both are produced synthetically.
Diamond enhancements are specific treatments performed on natural or
synthetic diamonds (usually those already cut and polished into a
gem), which are designed to better the gemological characteristics of
the stone in one or more ways. These include laser drilling to remove
inclusions, application of sealants to fill cracks, treatments to
improve a white diamond's color grade, and treatments to give fancy
color to a white diamond.
Coatings are increasingly used to give a diamond simulant such as
cubic zirconia a more "diamond-like" appearance. One such substance is
diamond-like carbon—an amorphous carbonaceous material that has some
physical properties similar to those of the diamond. Advertising
suggests that such a coating would transfer some of these diamond-like
properties to the coated stone, hence enhancing the diamond simulant.
Techniques such as
Raman spectroscopy should easily identify such a
Early diamond identification tests included a scratch test relying on
the superior hardness of diamond. This test is destructive, as a
diamond can scratch another diamond, and is rarely used nowadays.
Instead, diamond identification relies on its superior thermal
conductivity. Electronic thermal probes are widely used in the
gemological centers to separate diamonds from their imitations. These
probes consist of a pair of battery-powered thermistors mounted in a
fine copper tip. One thermistor functions as a heating device while
the other measures the temperature of the copper tip: if the stone
being tested is a diamond, it will conduct the tip's thermal energy
rapidly enough to produce a measurable temperature drop. This test
takes about 2–3 seconds.
Whereas the thermal probe can separate diamonds from most of their
simulants, distinguishing between various types of diamond, for
example synthetic or natural, irradiated or non-irradiated, etc.,
requires more advanced, optical techniques. Those techniques are also
used for some diamonds simulants, such as silicon carbide, which pass
the thermal conductivity test. Optical techniques can distinguish
between natural diamonds and synthetic diamonds. They can also
identify the vast majority of treated natural diamonds. "Perfect"
crystals (at the atomic lattice level) have never been found, so both
natural and synthetic diamonds always possess characteristic
imperfections, arising from the circumstances of their crystal growth,
that allow them to be distinguished from each other.
Laboratories use techniques such as spectroscopy, microscopy and
luminescence under shortwave ultraviolet light to determine a
diamond's origin. They also use specially made instruments to aid
them in the identification process. Two screening instruments are the
DiamondSure and the DiamondView, both produced by the DTC and marketed
by the GIA.
Several methods for identifying synthetic diamonds can be performed,
depending on the method of production and the color of the diamond.
CVD diamonds can usually be identified by an orange fluorescence. D-J
colored diamonds can be screened through the Swiss Gemmological
Diamond Spotter. Stones in the D-Z color range can be
examined through the DiamondSure UV/visible spectrometer, a tool
developed by De Beers. Similarly, natural diamonds usually have
minor imperfections and flaws, such as inclusions of foreign material,
that are not seen in synthetic diamonds.
Screening devices based on diamond type detection can be used to make
a distinction between diamonds that are certainly natural and diamonds
that are potentially synthetic. Those potentially synthetic diamonds
require more investigation in a specialized lab. Examples of
commercial screening devices are D-Screen (WTOCD / HRD Antwerp) and
Diamond Analyzer (Bruker / HRD Antwerp).
Occasionally large thefts of diamonds take place. In February 2013
armed robbers carried out a raid at Brussels Airport and escaped with
gems estimated to be worth $50m (£32m; 37m euros). The gang broke
through a perimeter fence and raided the cargo hold of a Swiss-bound
plane. The gang have since been arrested and large amounts of cash and
The identification of stolen diamonds presents a set of difficult
problems. Rough diamonds will have a distinctive shape depending on
whether their source is a mine or from an alluvial environment such as
a beach or river—alluvial diamonds have smoother surfaces than those
that have been mined. Determining the provenance of cut and polished
stones is much more complex.
Kimberley Process was developed to monitor the trade in rough
diamonds and prevent their being used to fund violence. Before
exporting, rough diamonds are certificated by the government of the
country of origin. Some countries, such as Venezuela, are not party to
the agreement. The
Kimberley Process does not apply to local sales of
rough diamonds within a country.
Diamonds may be etched by laser with marks invisible to the naked eye.
Lazare Kaplan, a US-based company, developed this method. However,
whatever is marked on a diamond can readily be removed.
Gemology and Jewelry portal
List of diamonds
List of largest rough diamonds
List of minerals
^ a b "Diamond". Mindat. Retrieved July 7, 2009.
^ "Diamond". WebMineral. Retrieved July 7, 2009.
^ Liddell, H.G.; Scott, R. "Adamas". A Greek-English Lexicon. Perseus
^ a b c Hershey, W. (1940). The Book of Diamonds. New York: Hearthside
Press. pp. 22–28. ISBN 1-4179-7715-9.
Pliny the Elder
Pliny the Elder (2004). Natural History: A Selection. Penguin Books.
p. 371. ISBN 0-14-044413-0.
^ "Chinese made first use of diamond". BBC News. May 17, 2005.
Retrieved March 21, 2007.
^ a b Epstein, E.J. (1982). "Have You Ever Tried To Sell a Diamond?".
The Atlantic. Retrieved May 5, 2009.
Lavoisier (1772) "Premier mémoire sur la destruction du diamant par
le feu" (First memoir on the destruction of diamond by fire), Histoire
de l'Académie royale des sciences. Avec les Mémoires de
Mathématique & de Physique (History of the Royal Academy of
Sciences. With the Memoirs of Mathematics and Physics), part 2,
Lavoisier (1772) "Second mémoire sur la destruction du diamant par le
feu" (Second memoir on the destruction of diamond by fire), Histoire
de l'Académie royale des sciences. Avec les Mémoires de
Mathématique & de Physique, part 2, 591-616.
Smithson Tennant (1797) "On the nature of the diamond,"
Philosophical Transactions of the Royal Society of London, 87 :
^ a b Hazen, R. M. (1999). The diamond makers. Cambridge University
Press. pp. 7–10. ISBN 0-521-65474-2.
^ Hesse, R. W. (2007). Jewelrymaking through history. Greenwood
Publishing Group. p. 42. ISBN 0-313-33507-9.
^ a b c d e f g h i j Cartigny, Pierre; Palot, Médéric; Thomassot,
Emilie; Harris, Jeff W. (30 May 2014). "
Diamond Formation: A Stable
Isotope Perspective". Annual Review of
Earth and Planetary Sciences.
42 (1): 699–732. doi:10.1146/annurev-earth-042711-105259.
^ a b c Erlich, Edward I.; Hausel, W. Dan (2002). Diamond
deposits : origin, exploration, and history of discovery.
Littleton, CO: Society for Mining, Metallurgy, and Exploration.
^ a b c d e f g h i j k l m n o p q r Shirey, Steven B.; Shigley,
James E. (1 December 2013). "Recent Advances in Understanding the
Geology of Diamonds". Gems & Gemology. 49 (4).
^ Carlson, R.W. (2005). The Mantle and Core. Elsevier. p. 248.
^ Deutsch, Alexander; Masaitis, V.L.; Langenhorst, F.; Grieve, R.A.F.
(2000). "Popigai, Siberia—well preserved giant impact structure,
national treasury, and world's geological heritage" (PDF). Episodes.
23 (1): 3–12. Archived from the original (PDF) on October 21, 2012.
Retrieved June 16, 2008.
^ King, Hobart (2012). "How do diamonds form? They don't form from
coal!". Geology and
Earth Science News and Information. geology.com.
Archived from the original on October 30, 2013. Retrieved June 29,
^ Pak-Harvey, Amelia (Oct 31, 2013). "10 common scientific
misconceptions". The Christian Science Monitor. Retrieved August 30,
^ Pohl, Walter L. (2011). Economic Geology: Principles and Practice.
John Wiley & Sons. ISBN 9781444394863.
^ Allaby, Michael (2013). "mobile belt". A dictionary of geology and
earth sciences (4th ed.). Oxford: Oxford University Press.
^ Kjarsgaard, B. A. (2007). "
Kimberlite pipe models: significance for
exploration". In Milkereit, B. Proceedings of Exploration 07: Fifth
Decennial International Conference on Mineral Exploration (PDF).
Decennial Mineral Exploration Conferences, 2007. pp. 667–677.
Retrieved 1 March 2018.
^ Tielens, A. G. G. M. (12 July 2013). "The molecular universe".
Reviews of Modern Physics. 85 (3): 1021–1081.
^ Kerr, R. A. (1 October 1999). "
Neptune May Crush
Diamonds". Science. 286 (5437): 25a–25.
^ Scandolo, Sandro; Jeanloz, Raymond (November–December 2003). "The
Centers of Planets: In laboratories and computers, shocked and
squeezed matter turns metallic, coughs up diamonds and reveals Earth's
white-hot center". American Scientist. 91 (6): 516–525.
Bibcode:2003AmSci..91..516S. JSTOR 27858301.
^ Kaplan, Sarah (25 August 2017). "It rains solid diamonds on Uranus
and Neptune". Washington Post. Retrieved 16 October 2017.
^ Max Planck Institute for Radio Astronomy (25 August 2011). "A planet
made of diamond". Astronomy magazine. Retrieved 25 September
^ Heaney, P. J.; Vicenzi, E. P.; De, S. (2005). "Strange Diamonds: the
Mysterious Origins of
Carbonado and Framesite". Elements. 1 (2): 85.
^ Shumilova, T.G.; Tkachev, S.N.; Isaenko, S.I.; Shevchuk, S.S.;
Rappenglück, M.A.; Kazakov, V.A. (April 2016). "A "diamond-like star"
in the lab. Diamond-like glass". Carbon. 100: 703–709.
^ Wei-Haas, Maya. "Life and Rocks May Have Co-Evolved on Earth".
Smithsonian. Retrieved 26 September 2017.
^ Wei, L.; Kuo, P. K.; Thomas, R. L.; Anthony, T.; Banholzer, W.
Thermal conductivity of isotopically modified single crystal
diamond". Physical Review Letters. 70 (24): 3764–3767.
^ a b Walker, J. (1979). "Optical absorption and luminescence in
diamond" (PDF). Reports on Progress in Physics. 42 (10): 1605–1659.
^ John, P.; Polwart, N.; Troupe, C. E.; Wilson, J. I. B. (2002). "The
oxidation of (100) textured diamond".
Diamond and Related Materials.
11 (3–6): 861. Bibcode:2002DRM....11..861J.
^ Gray, Theodore (September 2009). "Gone in a Flash". Popular Science:
^ Webster, R.; Read, P.G. (2000). Gems: Their sources, descriptions
and identification (5th ed.). Great Britain: Butterworth-Heinemann.
p. 17. ISBN 0-7506-1674-1.
^ Fukura, Satoshi; Nakagawa, Tatsuo; Kagi, Hiroyuki (November 2005).
"High spatial resolution photoluminescence and Raman spectroscopic
measurements of a natural polycrystalline diamond, carbonado". Diamond
and Related Materials. 14 (11-12): 1950–1954.
^ Garai, J.; Haggerty, S.E.; Rekhi, S.; Chance, M. (2006). "Infrared
Absorption Investigations Confirm the Extraterrestrial Origin of
Carbonado Diamonds". Astrophysical Journal. 653 (2): L153–L156.
arXiv:physics/0608014 . Bibcode:2006ApJ...653L.153G.
^ "Diamonds from Outer Space: Geologists Discover Origin of Earth's
Mysterious Black Diamonds". National Science Foundation. January 8,
2007. Retrieved October 28, 2007.
^ Neves, A. J.; Nazaré, M. H. (2001). Properties, Growth and
Applications of Diamond. Institution of Engineering and Technology.
pp. 142–147. ISBN 0-85296-785-3.
^ Boser, U. (2008). "Diamonds on Demand". Smithsonian. 39 (3):
^ Lee, J.; Novikov, N. V. (2005). Innovative superhard materials and
sustainable coatings for advanced manufacturing. Springer.
p. 102. ISBN 0-8493-3512-4.
^ Marinescu, I. D.; Tönshoff, H. K.; Inasaki, I. (2000). Handbook of
ceramic grinding and polishing. William Andrew. p. 21.
^ a b c d e f Harlow, G.E. (1998). The nature of diamonds. Cambridge
University Press. p. 223;230–249.
^ Improved diamond anvil cell allows higher pressures Physics World
^ a b Collins, A. T. (1993). "The Optical and Electronic Properties of
Semiconducting Diamond". Philosophical Transactions of the Royal
Society A. 342 (1664): 233–244. Bibcode:1993RSPTA.342..233C.
^ Landstrass, M. I.; Ravi, K. V. (1989). "Resistivity of chemical
vapor deposited diamond films". Applied Physics Letters. 55 (10):
975–977. Bibcode:1989ApPhL..55..975L. doi:10.1063/1.101694.
^ Zhang, W.; Ristein, J.; Ley, L. (2008). "Hydrogen-terminated diamond
Redox activity". Physical Review E. 78 (4): 041603.
^ Wissner-Gross, A. D.; Kaxiras, E. (2007). "
Diamond stabilization of
ice multilayers at human body temperature" (PDF). Physical Review E.
76: 020501. Bibcode:2007PhRvE..76b0501W.
^ Fujimoto, A.; Yamada, Y.; Koinuma, M.; Sato, S. (2016). "Origins of
sp3C peaks in C1s
X-ray Photoelectron Spectra of
Analytical Chemistry. 88: 6110.
^ Collins, A. T.; Kanda, Hisao; Isoya, J.; Ammerlaan, C. A. J.; Van
Wyk, J. A. (1998). "Correlation between optical absorption and EPR in
high-pressure diamond grown from a nickel solvent catalyst". Diamond
and Related Materials. 7 (2–5): 333–338.
^ Zaitsev, A. M. (2000). "Vibronic spectra of impurity-related optical
centers in diamond". Physical Review B. 61 (19): 12909.
^ Hounsome, L. S.; Jones, R.; Shaw, M. J.; Briddon, P. R.; Öberg, S.;
Briddon, P.; Öberg, S. (2006). "Origin of brown coloration in
diamond". Physical Review B. 73 (12): 125203.
^ Wise, R. W. (2001). Secrets Of The Gem Trade, The Connoisseur's
Guide To Precious Gemstones. Brunswick House Press.
pp. 223–224. ISBN 978-0-9728223-8-1.
^ Khan, Urmee (December 10, 2008). "Blue-grey diamond belonging to
King of Spain has sold for record 16.3 GBP". The Daily Telegraph.
London. Retrieved March 31, 2010.
^ Nebehay, S. (May 12, 2009). "Rare blue diamond sells for record
$9.5 million". Reuters. Retrieved May 13, 2009.
^ Pomfret, James (December 1, 2009). "Vivid pink diamond sells for
record $10.8 million". Reuters.
^ a b Read, P. G. (2005). Gemmology. Butterworth-Heinemann.
pp. 165–166. ISBN 0-7506-6449-5.
^ O'Donoghue, M. (1997). Synthetic, Imitation and Treated Gemstones.
Gulf Professional Publishing. pp. 34–37.
^ Adiga, A. (April 12, 2004). "Uncommon Brilliance". Time. Retrieved
November 3, 2008.
^ "Jwaneng". Debswana. Archived from the original on March 17, 2012.
Retrieved March 9, 2012.
^ a b c Tichotsky, J. (2000). Russia's
Diamond Colony: The Republic of
Sakha. Routledge. p. 254. ISBN 90-5702-420-9.
^ "Jews Surrender Gem Trade to Indians". Spiegel Online. May 15,
^ "The history of the Antwerp
Diamond Center". Antwerp World Diamond
^ "Commission Decision of 25 July 2001 declaring a concentration to be
compatible with the common market and the EEA Agreement". Case No
COMP/M.2333 – De Beers/LVMH. EUR-Lex. 2003.
^ "Business: Changing facets; Diamonds". The Economist. 382 (8517):
^ "Certainty in the
Watch Out For Tipping Points -
IDEX`s Memo". idexonline.com. Retrieved September 24, 2014.
^ "The Elusive Sparcle". The Gem &
Jewellery Export Promotion
Council. Archived from the original on June 16, 2009. Retrieved April
^ Even-Zohar, C. (November 6, 2008). "Crisis Mitigation at De Beers".
DIB online. Archived from the original on May 12, 2011. Retrieved
April 26, 2009.
^ Even-Zohar, C. (November 3, 1999). "
De Beers to Halve Diamond
Stockpile". National Jeweler. Archived from the original on July 5,
2009. Retrieved April 26, 2009.
^ "Judgment of the Court of First Instance of 11 July 2007 – Alrosa
v Commission". EUR-Lex. 2007. Retrieved April 26, 2009.
^ "Mining operations". The
De Beers Group. 2007. Archived from the
original on June 13, 2008. Retrieved January 4, 2011.
Alrosa to resume market diamond sales in May". RIA
Novosti. May 6, 2009. Retrieved May 25, 2009.
^ "Media releases – Media Centre – Alrosa". Alrosa. December 22,
2009. Archived from the original on August 20, 2013. Retrieved January
^ "Another record profit for BHP". ABC News. August 22, 2007.
Retrieved August 23, 2007.
^ "Our Companies". Rio Tinto web site. Rio Tinto. Archived from the
original on May 11, 2013. Retrieved March 5, 2009.
^ a b c Broadman, H. G.; Isik, G. (2007). Africa's silk road. World
Bank Publications. pp. 297–299. ISBN 0-8213-6835-4.
^ "Bourse listing". World Federation of
Diamond Bourses. Retrieved
February 12, 2012.
^ "North America
Diamond Sales Show No Sign of Slowing". A&W
diamonds. Archived from the original on January 6, 2009. Retrieved May
^ a b Pierson, Hugh O. (1993). Handbook of carbon, graphite, diamond,
and fullerenes: properties, processing, and applications. William
Andrew. p. 280. ISBN 0-8155-1339-9.
^ a b James, Duncan S. (1998). Antique jewellery: its manufacture,
materials and design. Osprey Publishing. pp. 82–102.
^ "The Classical and
Special Shapes of Diamonds".
kristallsmolensk.com. Retrieved July 14, 2015.
^ Prelas, Mark Antonio; Popovici, Galina; Bigelow, Louis K. (1998).
Handbook of industrial diamonds and diamond films. CRC Press.
pp. 984–992. ISBN 0-8247-9994-1.
^ "Gem Cutting". Popular Mechanics. Hearst Magazines. 74 (5):
760–764. 1940. ISSN 0032-4558.
^ Rapaport, Martin. "Keep the
Diamond Dream Alive". Rapaport Magazine.
Diamonds.net. Retrieved September 9, 2012.
^ a b JCK Staff (January 26, 2011). "10 Things Rocking the Industry".
JCK. Jckonline.com. Archived from the original on January 7, 2013.
Retrieved September 9, 2012.
^ Bates, Rob (January 14, 2011). "Interview with Forevermark CEO".
JCK. Jckonline.com. Archived from the original on November 28, 2012.
Retrieved September 9, 2012.
^ Harlow, George E. (1998). The nature of diamonds. Cambridge
University Press. p. 34. ISBN 0-521-62935-7.
^ Kogel, Jessica Elzea (2006). Industrial minerals & rocks.
Society for Mining, Metallurgy, and Exploration (U.S.). p. 416.
^ "The Australian
Diamond Industry". Archived from the original on
July 16, 2009. Retrieved August 4, 2009.
^ Erlich, Edward; Dan Hausel, W. (2002).
Diamond deposits: origin,
exploration, and history of discovery. SME. p. 158.
^ "Diamond: The mineral
Diamond information and pictures".
minerals.net. Retrieved September 24, 2014.
^ a b c "Industrial Diamonds Statistics and Information". United
States Geological Survey. Retrieved May 5, 2009.
^ a b Spear, K.E; Dismukes, J.P. (1994). Synthetic Diamond: Emerging
CVD Science and Technology. Wiley–IEEE. p. 628.
^ Holtzapffel, C. (1856). Turning And Mechanical Manipulation.
Holtzapffel & Co. pp. 176–178.
^ Coelho, R. T.; Yamada, S.; Aspinwall, D. K.; Wise, M. L. H. (1995).
"The application of polycrystalline diamond (PCD) tool materials when
drilling and reaming aluminum-based alloys including MMC".
International Journal of Machine Tools and Manufacture. 35 (5):
^ Sakamoto, M.; Endriz, J.G.; Scifres, D.R. (1992). "120 W CW
output power from monolithic AlGaAs (800 nm) laser diode array
mounted on diamond heatsink".
Electronics Letters. 28 (2): 197–199.
^ a b Yarnell, A. (2004). "The Many Facets of Man-Made Diamonds".
Chemical and Engineering News. 82 (5): 26–31.
^ a b "Conflict Diamonds". United Nations. March 21, 2001. Archived
from the original on March 9, 2010. Retrieved May 5, 2009.
^ Catelle, W. R. (1911). The Diamond. John Lane Company.
^ Ball, V. (1881). "Chapter 1". Diamonds,
Coal of India.
London: Trübner & Co. p. 1. Ball was a geologist in
^ "Biggest diamond found in Panna". Mail Today. July 1, 2010. Archived
from the original on July 7, 2011.
^ Shillington, K. (2005). Encyclopedia of African history. CRC Press.
p. 767. ISBN 1-57958-453-5.
^ a b Janse, A. J. A. (2007). "Global Rough
Diamond Production Since
1870". Gems & Gemology. 43 (2): 98–119.
^ a b Lorenz, V. (2007). "Argyle in Western Australia: The world's
richest diamantiferous pipe; its past and future". Gemmologie,
Zeitschrift der Deutschen Gemmologischen Gesellschaft. 56 (1–2):
^ a b Cooke, Sarah (October 17, 2004). "Microscopic diamond found in
Montana Standard. Archived from the original on January
21, 2005. Retrieved May 5, 2009.
^ Marshall, S.; Shore, J. (2004). "The
Diamond Life". Guerrilla News
Network. Archived from the original on January 26, 2007. Retrieved
March 21, 2007.
^ Shigley, James E.; Chapman, John; Ellison, Robyn K. (2001).
"Discovery and Mining of the Argyle
Diamond Deposit, Australia" (PDF).
Gems & Gemology. Gemological Institute of America. 37 (1):
26–41. doi:10.5741/GEMS.37.1.26. Archived from the original (PDF) on
September 30, 2009. Retrieved February 20, 2010.
^ a b Basedau, M.; Mehler, A. (2005). Resource politics in Sub-Saharan
Africa. GIGA-Hamburg. pp. 305–313.
World Federation of Diamond Bourses (WFDB) and International Diamond
Manufacturers Association: Joint Resolution of 19 July 2000. World
Diamond Council. July 19, 2000. ISBN 978-90-04-13656-4. Retrieved
November 5, 2006.
^ "Voluntary Code of Conduct For Authenticating Canadian Diamond
Claims" (PDF). Canadian
Diamond Code Committee. 2006. Retrieved
October 30, 2007.
^ Kjarsgaard, B. A.; Levinson, A. A. (2002). "Diamonds in Canada".
Gems and Gemology. 38 (3): 208–238. doi:10.5741/GEMS.38.3.208.
^ a b c "The Global
Diamond Industry: Lifting the Veil of Mystery"
(PDF). Bain & Company. Retrieved January 14, 2012.
^ 1Shigley, J.E.; Abbaschian, Reza; Shigley, James E. (2002). "Gemesis
Laboratory Created Diamonds". Gems & Gemology. 38 (4): 301–309.
^ Shigley, J.E.; Shen, Andy Hsi-Tien; Breeding, Christopher M.;
McClure, Shane F.; Shigley, James E. (2004). "Lab Grown Colored
Diamonds from Chatham Created Gems". Gems & Gemology. 40 (2):
^ Werner, M.; Locher, R (1998). "Growth and application of undoped and
doped diamond films". Reports on Progress in Physics. 61 (12): 1665.
^ Pisani, Bob (August 27, 2012). "The Business of Diamonds, From
Mining to Retail". CNBC.
^ Kogel, J. E. (2006). Industrial Minerals & Rocks. SME.
pp. 426–430. ISBN 0-87335-233-5.
^ O'Donoghue, M.; Joyner, L. (2003). Identification of gemstones.
Great Britain: Butterworth-Heinemann. pp. 12–19.
^ Barnard, A. S. (2000). The diamond formula. Butterworth-Heinemann.
p. 115. ISBN 0-7506-4244-0.
^ Shigley, J.E. (2007). "Observations on new coated gemstones".
Gemmologie: Zeitschrift der Deutschen Gemmologischen Gesellschaft. 56
^ US 4488821, Wenckus, J. F., "Method and means of rapidly
distinguishing a simulated diamond from natural diamond", published
December 18, 1984, assigned to Ceres
Electronics Corporation ;
U.S. Patent 4,488,821
^ a b Edwards, H. G. M.; Chalmers, G. M (2005).
Raman spectroscopy in
archaeology and art history. Royal Society of Chemistry.
pp. 387–394. ISBN 0-85404-522-8.
^ a b Welbourn, C. (2006). "Identification of Synthetic Diamonds:
Present Status and Future Developments". Gems and Gemology. 42 (3):
^ Donahue, P.J. (April 19, 2004). "DTC Appoints GIA Distributor of
DiamondSure and DiamondView". Professional Jeweler Magazine. Retrieved
March 2, 2009.
^ "SSEF diamond spotter and SSEF illuminator". SSEF Swiss Gemmological
Institute. Archived from the original on June 27, 2009. Retrieved May
^ "Arrests over $50m
Belgium airport diamond heist". BBC News. May 8,
^ "Who, What, Why: How do you spot a stolen diamond?". BBC News.
February 21, 2013.
^ "Brussels diamond robbery nets 'gigantic' haul". BBC News. February
C. Even-Zohar (2007). From Mine to Mistress: Corporate Strategies and
Government Policies in the International
Diamond Industry (2nd ed.).
Mining Journal Press.
G. Davies (1994). Properties and growth of diamond. INSPEC.
M. O'Donoghue (2006). Gems. Elsevier. ISBN 0-7506-5856-8.
M. O'Donoghue and L. Joyner (2003). Identification of gemstones. Great
Britain: Butterworth-Heinemann. ISBN 0-7506-5512-7.
A. Feldman and L.H. Robins (1991). Applications of
Diamond Films and
Related Materials. Elsevier.
J.E. Field (1979). The Properties of Diamond. London: Academic Press.
J.E. Field (1992). The Properties of Natural and Synthetic Diamond.
London: Academic Press. ISBN 0-12-255352-7.
W. Hershey (1940). The Book of Diamonds. Hearthside Press New York.
S. Koizumi, C.E. Nebel and M. Nesladek (2008). Physics and
Applications of CVD Diamond. Wiley VCH. ISBN 3-527-40801-0.
L.S. Pan and D.R. Kani (1995). Diamond: Electronic Properties and
Applications. Kluwer Academic Publishers.
Pagel-Theisen, Verena (2001).
Diamond Grading ABC: the Manual.
Antwerp: Rubin & Son. ISBN 3-9800434-6-0.
R.L. Radovic, P.M. Walker and P.A. Thrower (1965). Chemistry and
physics of carbon: a series of advances. New York: Marcel Dekker.
M. Tolkowsky (1919).
Diamond Design: A Study of the Reflection and
Refraction of Light in a Diamond. London: E. & F.N. Spon.
R.W. Wise (2016). Secrets of the Gem Trade: The Connoisseur's Guide to
Precious Gemstones (Second Edition). Brunswick House Press.
A.M. Zaitsev (2001). Optical Properties of Diamond: A Data Handbook.
Springer. ISBN 3-540-66582-X.
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Definitions from Wiktionary
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Quotations from Wikiquote
Properties of diamond: Ioffe database
"A Contribution to the Understanding of Blue Fluorescence on the
Appearance of Diamonds". (2007)
Gemological Institute of America (GIA)
Tyson, Peter (November 2000). "Diamonds in the Sky". Retrieved March
Have You Ever Tried to Sell a Diamond?
Allotropes of carbon
Lonsdaleite (hexagonal diamond)
Fullerenes (Buckminsterfullerene, C70, Higher fullerenes, Lower
fullerenes, Nanotubes, Nanobuds, Nanoscrolls)
Linear acetylenic carbon
mixed sp3/sp2 forms
Aggregated diamond nanorod
Repoussé and chasing
Wire wrapped jewelry
Precious metal alloys
Other natural objects
Gemmological Classifiactions by E. Ya. Kievlenko, 1980, updated
Natural marine pearls
Precious Black Opal
Yellow, Green, Violet Sapphires
Orange topaz (Imperial)
Precious White and Fire Opal
Tourmaline — Verdelite
Beryl — Heliodor, pink, yellow-green
Topaz yellow, blue, pink
Spessartine (malaya), Rhodolite, Almandine, Pyrope
Amber (Baltic amber)
Colorless, smoky and pink quartz
Opaque iridescent feldspars
Cacholong (Porouse opal)
Listwanite (green mica)