Diamond flaws are common. Few natural

diamond Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the Chemical stability, chemically stable form of car ...

s are perfect; most of them have

inclusion Inclusion or Include may refer to: Sociology * Social inclusion, aims to create an environment that supports equal opportunity for individuals and groups that form a society. ** Inclusion (disability rights), promotion of people with disabiliti ...

s or imperfections. These inclusions are also known as flaws and exist in various forms, such as exterior and interior. Inclusions are also classified in the manner in which they were formed. For example, syngenetic diamond inclusions are inclusions which were formed while a diamond formed, while

epigenetic In biology, epigenetics is the study of stable phenotypic changes (known as ''marks'') that do not involve alterations in the DNA sequence. The Greek prefix '' epi-'' ( "over, outside of, around") in ''epigenetics'' implies features that are "o ...

inclusions occurred after a diamond was formed.

Flaws

The presence or absence of flaws or inclusions in a diamond is usually decided by examining the stone carefully with a lens having the standard magnifications of 10x. No other magnification should be taken as authoritative. Stones which show no apparent flaws or inclusions under this magnification are regarded as flawless. The term for a scarcely perceptible inclusion is "VVS" for "very very slight (or small)" – which is sometimes offered as flawless. Slightly larger flaws or groups of very thin inclusions are termed "VS" ("very slight"). Larger flaws or inclusions are termed as "SI" (or slightly included). Even larger flaws are termed as "1st pique". Slightly larger flaws classify the stone as "2nd pique" and so on. Any flaws which are visible with the naked eye would be sufficient to scale the price down considerably.

External flaws

Blemishes

These diamond flaws are present on the surface of a stone and can occur naturally. However, these are more likely to be caused by the external environment when a diamond was being cut and polished.

Scratches

These are fine lines found on the surface of the diamond. They may have been present naturally or caused when a diamond was cut. While minor scratches can be removed through proper polishing, deep scratches can rarely be removed by treating the diamond.

Extra facets

These are usually cut to remove blemishes or certain close to surface inclusions on diamonds. At times these extra

facet Facets () are flat faces on geometric shapes. The organization of naturally occurring facets was key to early developments in crystallography, since they reflect the underlying symmetry of the crystal structure. Gemstones commonly have facets cut ...

s are also cut to enhance the brilliance of the diamond. These do not usually affect the clarity grade of a diamond.

Fracture

A breakage in diamonds that is not parallel to the

cleavage plane Cleavage, in mineralogy and materials science, is the tendency of crystalline materials to split along definite crystallographic structural planes. These planes of relative weakness are a result of the regular locations of atoms and ions in the ...

is referred to as a

fracture Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displa ...

. Fractures are usually irregular in shape, making a diamond look chipped. The practice of fracture filling is commonly employed to improve the

diamond clarity Diamond clarity is the quality of diamonds that relates to the existence and visual appearance of internal characteristics of a diamond called ''inclusions'', and surface defects, called ''blemishes''. Clarity is one of the four Cs of diamond grad ...

of such diamonds.

Fingerprints

Fingerprint A fingerprint is an impression left by the friction ridges of a human finger. The recovery of partial fingerprints from a crime scene is an important method of forensic science. Moisture and grease on a finger result in fingerprints on surfac ...

inclusions in the shape of fingerprints can sometimes be found in diamonds. However, such inclusions are rare in diamonds as compared to other stones, such as

rubies A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sap ...

. Such inclusions are usually formed during

fluid In physics, a fluid is a liquid, gas, or other material that continuously deforms (''flows'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are substances which cannot resist any shear ...

assisted partial healing of fractures already present in stones. For this to take place in diamonds, high temperatures and pressure (HTHP) are required, which is unusual. Few such inclusions have been reported in natural blue and colorless diamonds. While this could indicate that diamonds have been HTHP treated, giving the required temperatures for fingerprint inclusions, such is not always the case. The earth may also cause

geologically Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Eart ...

high temperatures, leading to the formation of fingerprint inclusions.

Pits

Small holes may be present on the surface of a diamond. These pits are usually not visible to the naked eye. However, pits present on the table facet of a diamond are usually visible and reduce the clarity of a diamond.

Nicks

Diamonds are also chipped at places causing the appearance of nicks. This is often repaired by adding extra facets. However, too many facets reduce the brilliance of a diamond and are to be avoided.

Naturals

This refers to the original surface of the diamond, which has been left alone and unpolished. Naturals are usually left on or near the

girdle A belt, especially if a cord or rope, is called a girdle if it is worn as part of Christian liturgical vestments, or in certain historical, literary or sports contexts. Girdles are used to close a cassock in Christian denominations, including th ...

of the diamond. While these are considered as blemishes, the presence of naturals is a sign of good cutting practice, where the cutter has managed to retain as much of the original weight as possible. Indented naturals are also seen to exist on some stones, where the portion of the natural is seen to dip inside slightly from the diameter of the stone. Here the cutter usually leaves the indented natural either at the girdle or

pavilion In architecture, ''pavilion'' has several meanings: * It may be a subsidiary building that is either positioned separately or as an attachment to a main building. Often it is associated with pleasure. In palaces and traditional mansions of Asia ...

of the stone, in order to keep it less noticeable. In such positions, the natural is not visible even with a

loupe A loupe ( ) is a simple, small magnification device used to see small details more closely. They generally have higher magnification than a magnifying glass, and are designed to be held or worn close to the eye. A loupe does not have an attached h ...

. Indents can be removed if the cutter polishes out more roughly. However, this would result in a drop of the diamond's weight by up to 25%.

Carbons

Diamonds are made from

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...

, usually

graphite Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large ...

. Nevertheless, while a diamond is being formed, it may not totally

crystallize Crystallization is the process by which solid forms, where the atoms or molecules are highly organized into a structure known as a crystal. Some ways by which crystals form are precipitating from a solution, freezing, or more rarely deposi ...

, leading to the presence of small dots of black carbon. These black spots have been classified to be those of graphite,

pyrrhotite Pyrrhotite is an iron sulfide mineral with the formula Fe(1-x)S (x = 0 to 0.2). It is a nonstoichiometric variant of FeS, the mineral known as troilite. Pyrrhotite is also called magnetic pyrite, because the color is similar to pyrite and it is ...

and

pentlandite Pentlandite is an iron–nickel sulfide with the chemical formula . Pentlandite has a narrow variation range in Ni:Fe but it is usually described as having a Ni:Fe of 1:1. It also contains minor cobalt, usually at low levels as a fraction of wei ...

. These surface flaws resemble a small black dot and may affect the clarity of the stone depending on the size of the imperfection. The occurrence of this kind of flaw is less common in diamonds compared to pinpoint inclusions. Carbons are usually seen in white or blue-white stones. Carbons are not commonly found in diamonds of poorer colors. Within the trade, these are called "carbon spots" and may be cleavage cracks which have developed through uneven heating or a blow. Cleavage cracks often appear to be dark or black in normal lighting conditions because of light reflection.

Chips

The breaking off of a small piece of diamond towards the surface is usually referred to as chipping. The term may be confused with "diamond chips", which refer to very small pieces of diamonds. These are usually caused due to minor impact from the environment. Downward impact caused when a stone is being set or is being worn, can cause chips on the

culet {{inline, date=November 2022 In gemology, a culet is a flat face on the bottom of a gemstone. During the 14th century, after the adoption of the table cut, a further facet was added to the bottom of the cut parallel to the surface of the tabl ...

of the diamond. As these are commonly caused when a diamond is worn, it is suggested that while diamonds are being set, a little space be left between the base of the diamond and the head of the prongs of the ring. This space acts as a cushion protecting the diamond from possible chipping when it falls. However, chips are easy to remove by treating the diamond.

Internal flaws

Every natural diamond crystal contains impurities and typical

intrinsic In science and engineering, an intrinsic property is a property of a specified subject that exists itself or within the subject. An extrinsic property is not essential or inherent to the subject that is being characterized. For example, mass ...

or "self-defects": vacancies,

dislocation In materials science, a dislocation or Taylor's dislocation is a linear crystallographic defect or irregularity within a crystal structure that contains an abrupt change in the arrangement of atoms. The movement of dislocations allow atoms to sl ...

s, and interstitial atoms. The most common impurity in diamond is

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

, which can comprise up to 1% of a diamond by mass. Nitrogen as a diamond impurity was first identified in 1959 by Kaiser and Bond of

Bell Telephone The Bell System was a system of telecommunication companies, led by the Bell Telephone Company and later by the American Telephone and Telegraph Company (AT&T), that dominated the telephone services industry in North America for over one hundre ...

Crystal/mineral inclusions

Some diamonds show the presence of small

crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...

s or other diamonds. These are classified in different categories depending on the size and structure of the inclusion. While many such inclusions are small and invisible to the naked eye, some diamonds may have large inclusions able to be seen with the naked eye, and can affect a diamond's clarity and life. Some crystals resemble a diamond inside a diamond and may also add to the appearance of the stone. These take on shapes of bubbles, needles or grains and are classified as below.

Pinpoint inclusions

As the name implies, these inclusions are minute crystals usually white in color present inside the diamond. These resemble a small point of light and are, by far, the most common of all flaws found in diamonds. Most pinpoint inclusions do not affect the clarity of a diamond and are not visible to the naked eye and are usually not indicated on the plotting diagrams of diamond reports. Comments such as "pinpoints not shown" may be listed in the comments section.

Needles

Diamond crystals in a diamond can also be present in the form of long and thin needles. These may not be visible to the naked eye, unless the needle inclusion is of a noticeable color or has a noticeable presence. Some needle inclusions are also known to give diamonds a special look.

Cloud

The presence of three or more pinpoint inclusions close together can create an area of

haze Haze is traditionally an atmospheric phenomenon in which dust, smoke, and other dry particulates suspended in air obscure visibility and the clarity of the sky. The World Meteorological Organization manual of codes includes a classification ...

, or a cloud, in the diamond. While the occurrence of a small cloud is not visible to the naked eye, presence of many pinpoints covering a large area can affect the clarity of the diamond. These are usually indicated on grading reports in the form of tiny red dots close together or as circles and other formations.

Knots

When diamond crystals extend to the surface of the diamond, they are referred to as knots. These can be viewed under proper lighting conditions with a diamond loupe. Certain knot formations may also cause raised areas on particular facets of the diamond. The presence of knots may affect both the clarity and durability of the diamond and are best avoided.

Graining

Crystal inclusions in diamonds occurs in the form of lines known as graining. Graining should not be confused with a rough diamonds natural grain lines . Graining forms due to the improper crystallization of the diamond or when a diamond is twinned. Twinned diamonds are two diamonds that have grown together and causes cross-grains within the diamond during its growth / crystallization process. Twinning causes natural lines, planes or cross-grains in a diamond. Graining can't be removed during the polishing process of a diamond as it is a natural plane within the diamond. Cross-graining also makes the polishing process extremely difficult for diamond cutters as a diamond only cuts against its natural grain lines and never with the grain. One will always find graining in rough diamonds known as "Macle's". Macles are easily identified by its triangular shape. The graining line on the Macle is a natural cleaving plane where the diamond can easily be split in half. Diamonds with graining will never be graded as Flawless as its maximum grade would only fetch Internally Flawless (IF). Although graining seems like a severe flaw it is not visible with the naked eye and does not impact the overall brilliance or quality of a diamond.

Feathers

These are cracks in the stone that resemble the design of feathers. The presence of feathers in a diamond usually does not affect the life of the stone unless and until the feather runs through a major length of the stone or shows major stress points where it can break. If the cracks reach the surface or have deep fissures, the durability of the stone may be reduced with the possibility of the stone breaking with age.

Intergrowths

Twinning wisps or intergrowths may also be seen in diamonds. These formations are usually inclusions in diamonds that have twisted together during the time of diamond formation. Thus, various inclusions such as pinpoints, needles or feathers may form together, creating a white strip inside the diamond. Surface graining may also be seen in some cases. Such intergrowths are more commonly seen in fancy cut diamonds and are extremely rare in ideal cut diamonds.

Cleavage

These are cracks in a diamond that occur in a straight line and are parallel to one of the diamond's

crystallographic planes Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids. Crystallography is a fundamental subject in the fields of materials science and solid-state physics (condensed matter physics). The word ...

. Cleavages are usually caused by deep internal strain in a diamond and could also have been caused by a strong blow to the diamond. It usually shows no feathers and has a great chance of causing the stone to split, especially if placed in the high pressure grip of prongs in rings. Stones with cleavage must be chosen carefully and avoided as often as possible.

Etch channel

Etch channels are created during a diamond's formation process deep in the Earth. In the journey of the rough diamond to the Earth's surface, the contact with high-temperature fluids etches into the diamond's crystalline structure which often leave parallel lines or irregularly shaped tunnel-like structures.http://onlinediamondbuyingguide.co
Etch Channels in Diamonds
Retrieved Jan 9, 2013

Bearding

Also known as girdle fencing or "dig marks", this is caused around the diamond's girdle as the diamond is cut or bruted. These fine lines usually resemble a strand of hair and do not present a problem. However, extensive bearding can lessen the brightness of the diamond. It is suitable that such diamonds be cut or polished again to improve luster. Diamond flaws are not always negative features. In fact, these flaws often lend a diamond its distinctive beauty and make a stone look unique.

References

*Gemlab.net. (2002b)
Defects produced in natural diamond by color treatments
Retrieved July 9, 2008. *GIA (200
"A Contribution to the Understanding of Blue Fluorescence on the Appearance of Diamonds"
Retrieved July 9, 2008. *About.com By Carly Wickel

Accessed July 9, 2008.

External links

{{DEFAULTSORT:Diamond Flaws Impact event minerals Economic geology Diamond