|
Diamond Simulant
A diamond simulant, diamond imitation or imitation diamond is an object or material with gemological characteristics similar to those of a diamond. Simulants are distinct from synthetic diamonds, which are actual diamonds exhibiting the same material properties as natural diamonds. Enhanced diamonds are also excluded from this definition. A diamond simulant may be artificial, natural, or in some cases a combination thereof. While their material properties depart markedly from those of diamond, simulants have certain desired characteristics—such as dispersion and hardness—which lend themselves to imitation. Trained gemologists with appropriate equipment are able to distinguish natural and synthetic diamonds from all diamond simulants, primarily by visual inspection. The most common diamond simulants are high- leaded glass (i.e., rhinestones) and cubic zirconia (CZ), both artificial materials. A number of other artificial materials, such as strontium titanate and syntheti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CZ Brilliant
CZ, C-Z, C/Z, or Cz may refer to: * Czech Republic, ISO 3166 country code CZ * .cz, internet country code top-level domain for the Czech Republic Businesses and organisations * C/Z Records, an American record label * Česká zbrojovka firearms (ČZ) ** Česká zbrojovka Uherský Brod, a Czech firearms manufacturer *** CZ-USA, U.S. division ** Česká zbrojovka Strakonice (ČZ a.s.), a Czech manufacturer of forklifts and formerly motorcycles and firearms * Cizeta, an Italian car manufacturer named for its founder, Claudio Zampolli (C.Z.) * China Southern Airlines, IATA airline designator CZ Science and technology * Cubic zirconia, a synthetic gemstone * Haplogroup CZ (mtDNA), in human mitochondrial genetics * Controlled Z gate, a type of Quantum logic gate * Long March (rocket family), or Chang Zheng * Cz, an EEG electrode site according to the 10-20 system * Changpeng Zhao, founder and CEO of cryptocurrency exchange Binance Other uses * Cz (digraph), in the Polish language * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jewelry
Jewellery ( UK) or jewelry ( U.S.) consists of decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a western perspective, the term is restricted to durable ornaments, excluding flowers for example. For many centuries metal such as gold often combined with gemstones, has been the normal material for jewellery, but other materials such as glass, shells and other plant materials may be used. Jewellery is one of the oldest types of archaeological artefact – with 100,000-year-old beads made from '' Nassarius'' shells thought to be the oldest known jewellery.Study reveals 'oldest jewellery' , '' |
Specific Gravity
Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest (at ); for gases, the reference is air at room temperature (). The term "relative density" (often abbreviated r.d. or RD) is often preferred in scientific usage, whereas the term "specific gravity" is deprecated. If a substance's relative density is less than 1 then it is less dense than the reference; if greater than 1 then it is denser than the reference. If the relative density is exactly 1 then the densities are equal; that is, equal volumes of the two substances have the same mass. If the reference material is water, then a substance with a relative density (or specific gravity) less than 1 will float in water. For example, an ice cube, with a relative density of about 0.91, will float. A substance with a relative density grea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleavage (crystal)
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 crystal, which create smooth repeating surfaces that are visible both in the microscope and to the naked eye. If bonds in certain directions are weaker than others, the crystal will tend to split along the weakly bonded planes. These flat breaks are termed "cleavage."Hurlbut, Cornelius S.; Klein, Cornelis, 1985, '' Manual of Mineralogy'', 20th ed., Wiley, The classic example of cleavage is mica, which cleaves in a single direction along the basal pinacoid, making the layers seem like pages in a book. In fact, mineralogists often refer to "books of mica." Diamond and graphite provide examples of cleavage. Both are composed solely of a single element, carbon. But in diamond, each carbon atom is bonded to four others in a tetrahedral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corundum
Corundum is a crystalline form of aluminium oxide () typically containing traces of iron, titanium, vanadium and chromium. It is a rock-forming mineral. It is a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure. Corundum has two primary gem varieties: ruby and sapphire. Rubies are red due to the presence of chromium, and sapphires exhibit a range of colors depending on what transition metal is present. A rare type of sapphire, padparadscha sapphire, is pink-orange. The name "corundum" is derived from the Tamil- Dravidian word ''kurundam'' (ruby-sapphire) (appearing in Sanskrit as ''kuruvinda''). Because of corundum's hardness (pure corundum is defined to have 9.0 on the Mohs scale), it can scratch almost all other minerals. It is commonly used as an abrasive on sandpaper and on large tools used in machining metals, plastics, and wood. Emery, a variety of corundum with no val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scratch Plate
A pickguard (also known more correctly as scratchplate) is a piece of plastic or other (often laminated) material that is placed on the body of a guitar, mandolin or similar plucked string instrument. The main purpose of the pickguard is to protect the guitar's finish from being scratched by the nails of the picking hand, as it was included on guitars not played with a plectrum. The pick does not normally contact that part of the guitar when used correctly. As well as serving a practical purpose, the pickguard may also be used for decoration and is often made in a contrasting color to that of the guitar body (popular variants are white pickguards on darker guitars and black pickguards on lighter guitars). As well as plastic, other pickguard materials can include acrylic glass, glass, plywood, fabrics, metal, and mother-of-pearl/pearloid varieties. Expensive guitars may have luxury pickguards made from exotic woods, [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardness Point
In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example hard metals such as titanium and beryllium are harder than soft metals such as sodium and metallic tin, or wood and common plastics. Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, hardness can be measured in different ways, such as scratch hardness, indentation hardness, and rebound hardness. Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter. Measuring hardness There are three main types of hardness measurements: ''scr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Flaws
Diamond flaws are common. Few natural diamonds are perfect; most of them have inclusions 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 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" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 into them in order to improve their appearance by allowing them to reflect light. Facet arrangements Of the hundreds of facet arrangements that have been used, the most famous is probably the round brilliant cut, used for diamond and many colored gemstones. This first early version of what would become the modern Brilliant Cut is said to have been devised by an Italian named Peruzzi, sometime in the late 17th century.Gems, 5th edition, Webster, 1995.Gemstones of the world, Schumann, 1977. Later on, the first angles for an "ideal" cut diamond were calculated by Marcel Tolkowsky in 1919. Slight modifications have been made since then, but angles for "ideal" cut diamonds are still similar to Tolkowsky's formula. Round brilliants cut bef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lustre (mineralogy)
Lustre (British English) or luster (American English; see spelling differences) is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the Latin ''lux'', meaning "light", and generally implies radiance, gloss, or brilliance. A range of terms are used to describe lustre, such as ''earthy'', ''metallic'', ''greasy'', and ''silky''. Similarly, the term ''vitreous'' (derived from the Latin for glass, ''vitrum'') refers to a glassy lustre. A list of these terms is given below. Lustre varies over a wide continuum, and so there are no rigid boundaries between the different types of lustre. (For this reason, different sources can often describe the same mineral differently. This ambiguity is further complicated by lustre's ability to vary widely within a particular mineral species). The terms are frequently combined to describe intermediate types of lustre (for example, a "vitreous greasy" lustre). Some minerals exhibit unu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 handle, and its focusing lens(es) are contained in an opaque cylinder or cone. On some loupes this cylinder folds into an enclosing housing that protects the lenses when not in use. Optics Three basic types of loupes exist: * Simple lenses, generally used for low-magnification designs because of high optical aberration. * Compound lenses, generally used for higher magnifications to control optical aberration. * Prismatic, multiple lenses with prisms. Uses Loupes are used in many professions where magnification enables precision work to be done with greater efficiency and ease. Examples include surgery, dentistry, ophthalmology, the jewelry trade, gemology, and watchmaking. Loupes are also sometimes used in photography and printing. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microscope
A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisible to the eye unless aided by a microscope. There are many types of microscopes, and they may be grouped in different ways. One way is to describe the method an instrument uses to interact with a sample and produce images, either by sending a beam of light or electrons through a sample in its optical path, by detecting photon emissions from a sample, or by scanning across and a short distance from the surface of a sample using a probe. The most common microscope (and the first to be invented) is the optical microscope, which uses lenses to refract visible light that passed through a thinly sectioned sample to produce an observable image. Other major types of microscopes are the fluorescence microscope, electron microscope (both the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
