"HOW TO BUY A DIAMOND WITHOUT GETTING RIPPED OFF"
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A B C D E F G H I J K L M N O P Q R S T V Z
AGS: Abbreviation for “American Gem Society”
Alexandrite: A transparent variety of the mineral chrysoberyl that is green by daylight and red (preferably) to almost violet in incandescent artificial light. The finest comes from Ceylon, good from Russia. It is one of the birthstones for June.
Alloy: A compound metal resulting from melting two or more metals together. Sterling silver, for example, is composed of 92.5% pure silver and 7.5% pure copper.
American cut: See Ideal cut.
Amethyst: A transparent, pale-violet to deep-purple variety of crystalline quartz. Major sources: Siberia, Brazil, Uruguay. It is the February birthstone.
Aquamarine: The transparent, very light to medium-dark blue to greenish-blue variety of beryl. Major sources: Brazil, Ceylon. Also found in California and Colorado. It is the birthstone for March.
Artificial stone: Manmade imitation or synthetic stone.
Assembled stone: Any stone constructed of two or more parts of gem materials, or one of gem and one of glass.
Baguette: From the French, meaning rod. A style of step cutting for small, rectangular shaped diamonds.
Baroque: In the jewelry field, baroque means irregular in shape. Mostly used for irregular “baroque” pearls.
Bead setting: A setting in which the prongs are formed (raised) by an engraving tool to secure the stone in a setting. These prongs are then rounded and pushed over the edge of a stone with a beading tool.
Bearded girdle: If a diamond is rounded up carelessly in the fashioning (polishing) process the surface of the girdle will turn out rough and numerous minute hair-like fractures are likely to extend a short distance into the stone.
A girdle with this appearance is referred to as being bearded. A diamond is also referred to a bearded if it has small chips and abrasions (usually from hard wear) on its girdle.
Beryl: A mineral species that includes the gem varieties emerald, aquamarine and morganite.
Bezel setting: A style of setting which encloses the girdle of a stone. A stone is placed into a tube, the top of which is then hammered over the girdle completely encircling and securing it.
Black diamond: When a diamond is dark gray, a very dark green or truly black, it is referred to as a black diamond. Such a stone may be opaque to nearly semitransparent.
Blemish: Any surface imperfection on a cut diamond. Such as a nick, knot, scratch, abrasion, minor crack or cavity.
Blue ground: Unoxidized rock in diamond pipes.
Blue-white: A term that has been used to refer to a diamond without body color. Unfortunately it is applied frequently (incorrectly and fraudulently) to diamonds that have a distinct yellow tint. Federal Trade Commission rulings state that it is an unfair trade practice to apply the term to any stone having a body color other than blue or bluish. An American Gem Society ruling prohibits the use of the term by its members. Flagrant misuse has made the term totally meaningless. The term is rarely used today, and if, it is usually for deceptive purposes to imply a better color.
Body color: The color of a diamond when examined under a diffused light against a hueless background free from surrounding reflections. The diffused light eliminates glaring reflections and dispersion, which would otherwise influence the color determination.
Bort: Diamonds fit for industrial / mechanical purposes only.
Bourse: French, meaning an exchange or meeting place where merchants transact business. The word is often used for a diamond dealers club or organization.
Brilliancy: The total amount of light reflected from both the interior and exterior surfaces of a gemstone. The amount of brilliancy also depends on the cutting, transparency, facet angles, proportions and polish.
Brilliant-cut (round): The most common style of cutting for diamonds and other stones. The standard round brilliant consists of a total of 58 facets: 1 table, 8 bezel facets, 8 star facets and 16 upper-girdle facets and usually a culet on the pavilion. Modifications of the brilliant style of cutting include such fancy shapes as the marquise, oval, pear shape and many others.
Bywater: Decidedly yellowish diamond.
Canary diamond: An intensely colored yellow diamond. The yellow must be vivid and deep enough to be an asset. Such a diamond is called a fancy.
Cape: A broad range of diamond color grades for stones that show a distinct yellow tint. The term originally referred to the Cape of Good Hope, South Africa. Since the average color produced by the South African mines was distinctly more yellow than the Brazilian average, the term cape became accepted for strongly yellow-tinted stones.
Carat: A unit of weight for diamonds and other gems. The metric carat of 0.200 grams, or 200 milligrams, was adopted in the United States in 1913 and is now standardized in the principal countries of the world. Not to be confused with karat. Karat refers only to the fineness of pure gold and gold alloys.
Carbon: An inclusion in a diamond that appears black to the unaided eye. Usually carbon (graphite) or small particles of another mineral. Some inclusions that appear black are actually reflections caused by cleavages (small cracks) or included transparent crystals.
Certified Diamond: See Diamond Certificate.
Certified Gemologist: A title awarded by the American Gem Society. To qualify, a person must study colored stones and their identification and diamond grading and appraising. After passing an extensive test he is awarded this title.
Champagne diamond: A greenish-yellow diamond of sufficiently pronounced color to be a positive asset. Also called a fancy.
Channel setting: Stones set between two ridges of metal with their edges almost touching, usually in a straight line. The sides of the mounting are hammered over to grip the outer edges (girdles) of the stone.
Chip: A small rose-cut or single-cut diamond. Also a break (chip) on a diamond that extends from a surface edge.
Chrysoberyl: A very hard and important gem species, of which cat’s-eye, alexandrite, and green, brown and yellow chrysoberyl are varieties. Sources: Ceylon, Russia, Brazil and China.
Citrine: The transparent yellowish to red-orange to red-brown variety of crystalline quartz. Citrine is often incorrectly referred to as topaz. Major sources: Brazil, Madagascar and Spain. It is one of the birthstones for November.
Clarity grade: The relative position of a diamond on a flawless-to-imperfect scale. The most common today is the scale used by the GIA.
Clean: A term used by some jewelers to indicate the absence of imperfections in a diamond. It is often misused to describe diamonds with slight imperfections. The AGS prohibits the use of the term clean or cleanish by its members.
Cleavage: A term to describe a break within a diamond. Usually the cleavage crack extends to the surface. It is the most damaging kind of imperfection in a diamond, since it affects durability as well as beauty. Also a term sometimes used for a diamond crystal that requires cleavage (splitting) before being cut and polished.
Cloud: A group of tiny white inclusions in a diamond that together give a cottony or clouded appearance. A cloud is sometimes large enough to deprive the entire stone of brilliancy.
Cluster setting: Stones set in a group to give the illusion of one larger stone and held by beaded prongs. Usually round clusters consist of six stones arranged around a single center stone.
Coated diamond: Also - painted diamond. A diamond that has been coated with a substance that imparts a bluish color to mask a yellowish body color. Painting diamonds is a deceptive practice.
Cocktail ring: A fancy design ladies ring using small diamonds and often small colored stones.
Coin gold or coin silver: Consists of 10% pure copper and 90% pure gold or silver.
Colored diamond: Referred to as “fancy diamonds” they occur in yellow, brown, pink, red, blue and green.
Color grade: The relative position of a diamond’s body color on a colorless (starting with D) to yellow (Z) scale.
Colorimeter: An instrument for measuring color. In 1955 the AGS developed an electronic colorimeter. It uses a selenium cell that can measure the relative transmission of yellow and blue light by a diamond.
Colorless diamond: A diamond totally devoid of any body color.
Commercially clean or commercially perfect: The common meaning of this term is “reasonably free from inclusions” implying that the diamond is “almost perfect.” Sometimes heavily flawed diamonds are represented in an obvious attempt to mislead as “commercially clean.” This term, because of its fraudulent nature, is prohibited by the AGS and the Federal Trade Commission.
Commercial white: A misleading term that is used to mean not white, but slightly off color. Often misused, the AGS and the FTC prohibits use of this term.
Crown: Referring to the portion of a faceted diamond (or other gemstone) above the girdle.
Cubic Zirconia: A man-made material without a natural counterpart that can be used as a diamond substitute. It has a 2.15 refractive index and a hardness of about 8 1/2. Was originally manufactured in Russia, Switzerland and Cambridge, Massachusetts.
Culet: The small facet that is polished parallel to the table across what would otherwise be the sharp point which terminates the pavilion (bottom) of a diamond. Its function is to reduce the possibility of damage to the stone.
Cushion cut: Much like the old-mine-cut, an older form of the brilliant cut, having a girdle outline approaching a square with rounded corners.
Cyclotron-treated-diamond: A diamond whose color has been changed as a result of bombardment with alpha, neutron or deuteron particles in a cyclotron particle accelerator.
Dark-field illumination: A method of illuminating diamonds and other gemstones with a strong light from the side while the stone is being viewed against a black background. It causes some inclusions and imperfections to stand out clearly.
De Beers Consolidated Mines, Ltd.: Popularly referred to as “The Syndicate” this company is the major factor in the diamond industry. It holds controlling interests in a number of diamond-mining companies. It owns and controls all of the important mines in South Africa.
Depth percentage: The depth of a polished diamond measured from the table (top) to the culet (bottom), expressed as a percentage of the stone’s diameter at the girdle, an important factor in grading proportions.
Diamond: A mineral composed of carbon crystallized into a cubic crystal system by intense heat and pressure. It is the hardest of all natural substances (10 on Moh’s scale) and one of the most highly valued of all gemstones. It ranges in color from colorless to yellow, brown, orange, green, blue and violet. Reddish stones are extremely valuable. Birthstone for April.
Diamond anniversary: An anniversary celebrated 65 and 75 years following the event.
Diamond Certificate: A certificate issued to a diamond by the Gemological Institute of America (GIA) or others, upon successfully passing the diamond-grading. The Certificate gives a complete and detailed description of the diamond, listing the 4C’s.
Dispersion: The breakup of a light ray into colors of the spectrum.
Dop : Device for holding diamond during the process of cutting and polishing.
dwt.: The abbreviation for pennyweight, a unit of weight for precious metal.
Eight cut: See single cut.
Electron-bombarded diamond: A diamond whose color has been changed to blue by bombarding it with electrons in a Van de Graff generator. Gamma-ray radiation has also been used to produce blue colors.
Emerald: Medium-light to dark green tones of beryl. There is no
standard dividing line between emerald and either aquamarine or the lighter green variety known as green beryl. A fine emerald is one of the four most valuable gems, the finest material comes from Colombia. Other sources are Russia, Brazil, India and Africa. It is the birthstone for May.
Emerald triplet: An assembled stone. Two parts, the top and the bottom are either quartz, pale beryl or synthetic spinel and the third part usually is a layer of green cement, serving a colorant while gluing the top to the bottom. The best way to detect these stones are by observing the side while immersed in a clear liquid.
Emerald cut: A form of “step cutting”. Usually rectangular, it has rows (steps) of elongated facets on the crown and pavilion, parallel to the girdle. It also has very pronounced corner facets.
Engagement ring: A ring given as token of betrothal, especially a diamond solitaire.
Eternity ring: The diamond eternity ring is a circlet of small diamonds set in gold or platinum. This type of ring has been used in Europe for hundreds of years as the traditional symbol of eternity. Very popular as a diamond wedding band.
European cut: Obsolete brilliant diamond cut, characterized by a very small table, a heavy crown, and great overall depth. Not to be confused with old-mine cut.
Extra facets: Facets in excess of those needed to achieve a given style of cutting. They usually result from polishing away nicks, chips, naturals, etc., on or near the surface. Although extra facets are considered blemishes, most jewelers disregard them if they are not visible from above.
Eye clean: A term that implies that no internal flaws are visible to the unaided eye of a qualified Gemologist. Because of its frequent use as a misleading and deceptive term the AGS and the FTC prohibit its use.
Facet: A plane (flat) polished surface on a gemstone.
Fancy cut: Any style of diamond cutting other than the round brilliant or single cut. Fancy cuts include the marquise, emerald cut, heart shape, pear shape and others.
Fancy diamond: Any diamond with a natural body color strong enough to be attractive, rather than just off color. Red, blue and green are very rare; orange and violet, rare; strong yellow, yellowish-green, brown and black stones are more common.
Feather: When the plane of cleaving or fracture in a diamond is viewed at right angles to it, the appearance is often reminiscent of a feather. Thus, cleavage and fracture cracks in diamonds are often called feathers.
Federal Trade Commission (FTC): A United States Government body that oversees interstate commerce and cooperates with representatives of various industries, to establish trade-practice rules that govern the representation to the public of the products of those industries.
Fine gold: Pure gold of 24-karat quality.
Finish: The quality of a diamond's polish, smoothness, symmetry and size of the culet.
Fire: Flashes of the different spectrum colors from dispersion.
Fisheye: A diamond whose pavilion (bottom) is exceedingly shallow, producing a glassy appearance and a noticeable lack of brilliancy. Also called shallow, spread or swindle cut.
Flaw: Any external or internal imperfection on or in a polished diamond; feather, fissure, carbon spot, knot, natural, cleavage, chip, inclusions, etc. The term flaw and imperfection are usually used interchangeably.
Flawless: A diamond without any blemishes or imperfections as seen under 10x magnification.
Fluorescence: Under different rays, ultraviolet, cathode, or x-ray some diamonds fluoresces different colors.
Four C’s: A phrase coined for advertising purposes that sums up the numerous factors affecting diamond value into four categories: color, clarity, cutting and carat weight.
Four grainer: See Grainer.
Full-cut brilliant: A brilliant-cut diamond or colored stone with the usual total of 58 facets. See Ideal-cut.
Garnet: Dark red Birthstone for January.
Gem: A cut-and-polished stone of beauty to be used in jewelry. Also used as a prefix for exceptional quality; e. g. a gem diamond (be careful, not a proper term as its use depends on the ethics of the seller.)
Gemologist: A specialist in gem materials. One who has successfully completed the study of gem identification, grading and pricing. Most common, Graduate Gemologist, who is certified by the GIA.
GIA (Gemological Institute of America): A nonprofit, endowed, educational Institution controlled by by jewelers and maintained for the benefit of the industry and the public. Most important diamond grading Laboratory, located in New York, NY and Santa Monica / Los Angeles, CA.
Girdle: The outer edge, the perimeter or dividing line between crown and pavilion on a cut and polished stone.
Glets ( or gletz): A word of Dutch origin for a cleavage crack in a diamond that looks like a feather.
Gold: A yellow-colored metallic element and precious metal, used for coins and jewelry for thousands of years. It is impervious to corrosion and oxidation. It is the most ductile and malleable of all metals.
Grain: The cleavage direction.
Grain mark: Line on the facet surface due to imperfect polishing.
Grainer: Diamonds with weights near multiples of one-quarter carat, or one grain are referred to as grainers; e. g. four-grainer for a one carat stone (be careful, this is an approximate, a four-grainer can be smaller than a one carat.)
Heat treatment (of diamond): Heating a diamond or other gem material at a given temperature for a specified period to permit a partial or complete readjustment of the atomic structure that was previously altered by some type of treatment. For example, an irradiated diamond that has turned green may be changed to other colors by heat treatment.
Hopetown: A town in Cape Province, South Africa. It was the location of the discovery of South Africa’s first diamond in 1886.
Ideal-cut or American-cut: Proportions and facet angles calculated by Marcel Tolkowsky to maximize brilliancy in a round diamond. The table is 53% of the stones diameter; depth is 60.3%; crown 16.2%; pavilion 43.1%; and the girdle 1%.
Illusion setting: A prong setting with a wide rim of white gold surrounding the diamond, either highly polished to act as a mirror or cut up to look like diamond facets. This setting appears as a continuation of the stone. The purpose is to create the illusion that the stone is larger than its actual size.
Imperfection: A term used to refer to any internal or external flaw on a cut and polished diamond.
Inclusion: Any visible internal foreign object in a diamond is called an inclusion.
Internally flawless: Describes a diamond without any internal flaws, but has minor surface blemishes, such as such as scratches, etc.. Usually such stones can be improved to “flawless” by re-polishing at a small loss of weight.
Irradiated diamond: A diamond that has been subjected to bombardment by electrons, neutrons or other atomic particles. Its purpose is to make the diamond’s color more attractive and desirable.
Jager: Term for a fine white diamond.
Jewelers’ Board of Trade: A National nonprofit Jewelers Association dating back to 1874. Its most important purpose is to keep track of credit ratings of jewelry manufacturers, wholesalers and retailers.
Jewelers’ Security Alliance of the United States: A nonprofit, voluntary Association of Jewelers, established in 1883. the main purpose is to prevent and guard against crimes committed against or by members of the jewelry trade.
Jeweler Vigilance Committee: The JVC was founded in 1913 to advance ethical practices in the jewelry industry. Its main objective is to protect the jewelry trade’s prestige and reputation, especially to maintain public confidence. To help maintain fair competition within the jewelry industry and to maintain trade standards, also to enforce truth in advertising and other laws and regulations.
Karat: A unit of weight to express the quality of a gold alloy, such as 18 karat or 14 karat. Pure gold is 24 karat. The word is spelled karat when applied to precious metals, and carat when applied to weight of gemstones.
Keystone: A retail keystone price means the cost of a jewelry item is 50% of that figure, of if you will, a 100% retail markup.
Knife-edge girdle: A very thin, knife-edge like girdle on a diamond. Not very desirable, since such a girdle is vulnerable to chipping.
Knot: A diamond crystal within a diamond that is most noticeable at the surface of a stone and stands out as a small, raised surface or bump.
Lapidary: A cutter and polisher of colored gemstones, as opposed to a diamond cutter, who only polishes diamonds.
Laser drilling: Technique of enhancing the clarity of a diamond by providing access for bleaching agents to inclusions in a diamond. The drill hole is less than 5/1000th of an inch in diameter and is only visible under magnification.
Lead glass: A glass that contains a large proportion of lead oxide. The addition of this oxide raises the refractive index and makes it much more brilliant than ordinary glass. It was the most common glass imitation of diamond.
Light-field illumination: A type of illumination that places the light source directly behind the diamond or other gemstone being observed.
Light yellow: A term used by some dealers to cover a wide range of
colors in the low end of the diamond color-grading scale. These stones show a very obvious yellow tint.
Loupe: A small jeweler’s magnifying glass. Most have a two lens (corrected) system and are of 10x power.
“Loupe clean”: A misleading term, since it suggests that no flaws are visible at less than 10X power magnification. Prohibited by the AGS and the Federal Trade Commission.
Luster: The quality of light reflected from the diamond.
Make: A trade term that refers to the proportions and finish of a polished diamond, as in good make or poor make.
Marquise cut: A style of diamond cutting in which the outline of the girdle is boat shaped.
Master stones: Polished diamonds, or more recently Cubic Zirconia, of known color grades that are used as comparison when grading diamonds for body color.
Milky diamond: A diamond that has a milky, dull or hazy appearance, usually caused by clouds of microscopic inclusions.
Moe gauge: A caliper-type gauge that, together with accompanying tables, is used to estimate the approximate weight of a mounted round brilliant-cut diamond by measuring its diameter and depth.
Mohs' scale: The most commonly used scale of relative hardness of minerals: diamonds, 10; corundum (ruby and sapphire), 9; topaz, 8; quartz, 7; feldspar, 6; apatite, 5; fluorite, 4; calcite, 3; gypsum, 2; talc, 1.
The divisions are not equal, for example, the difference between 9 and 10 is much greater than the entire difference between 9 and 1.
Murfreesboro: Arkansas town in Pike County near the largest diamond bearing kimberlite pipe in the united States. The Crater of Diamonds State Park is 2 1/2 miles south of Murfreesboro where visitors (for a small fee) can search for diamonds.
Natural: A term for a portion of the original surface of a rough diamond that is sometimes left by the cutter on a polished stone (usually on the girdle) to preserve a larger size and carat weight.
Nick: A minor chip out of the surface of a polished diamond, usually caused by a light blow.
Off-color diamond: Any diamond that has a tinge of undesirable color, especially yellowish, brownish or grayish.
Old-mine cut: An early form of a brilliant-cut with a nearly square or cushion-shape outline. Not to be confused with European-cut.
Old-miner: Abbreviation of old-mine cut.
Opal: An amorphous mineral. In great demand as a gemstone because of its unique display of multiple colors. Mostly found in Australia. October birthstone.
Oval cut: A brilliant style of cutting in which the outline is elliptical or oval.
Pave setting: A number of small stones set (paved) very close together, so as to show the least amount of metal. The stones are fitted into drilled holes and metal beads (small prongs) are pushed over the edge of the stones to hold them.
Pavilion (or base): That portion of a polished diamond below the girdle.
Pear-shape cut: A variation of the brilliant cut, having a pear-shaped girdle outline.
Peridot: A yellowish-green gemstone. Sources: St. John’s Island (Red Sea), Burma, Ceylon and Arizona. It is the birthstone for August.
Platinum: A soft, heavy, light gray precious metal. Alloyed with 5% or 10% iridium it is used in the most expensive jewelry.
Point: One carat of diamonds is divided into one-hundred parts. Each one-hundredth being called a point; e.g., one third of a carat (or 0.33 ct.) is called 33 points, a half carat (0.50 ct.) is called 50 points, etc..
Polished girdle: A girdle that has been lapped (polished) into a
smooth, polished surface, or more commonly into a series of flat, polished facets. As opposed to a dull-looking unpolished girdle.
Practical Fine Cut Brilliant: This cut originated from practice and serves as the standard cut for judging proportions in Germany. Respective of the girdle diameter, the crown height is 14.4%, the pavilion depth is 43.2%, the table diameter is 56.0%, and the crown height to pavilion depth ratio is 1: 3.00. The crown angle is 33.2 degree and the pavilion angle is 40.8 degrees.
Prong: The projection of metal that overlaps the edge of a stone and secures it to the setting.
Premier: Diamond from the Premier Mines; as commonly used, diamond having an oily luster or false color.
Proportions: The distribution of mass of a polished diamond above and below the girdle. The proportions are mathematically derived for the optimum treatment of light. Proper proportions are the most important factor in bringing out the beauty of a polished diamond.
Quartz: The most common and widely known mineral. It includes many varieties of gemstones in a great variety of colors. Among the best known are amethyst, citrine, smoky-quartz, aventurine, agate, tiger’s-eye and others.
Re-cutting: Refinishing a polished stone to improve its clarity grade or to update and modernize an old style cut.
Red diamond: The rarest of all fancy-colored diamonds. Ruby red stones are virtually unknown. Most so-called red diamonds are actually reddish-brown, rose-colored or pale pink stones.
Refractive index (R.I.): The measurement of how much a light ray is bent and reflected as it enters or leaves a gemstone. Generally, the higher the R.I. the greater the brilliancy of the stone.
Rhodium: A metal of the platinum group. Frequently used to plate silver to prevent tarnish, or to plate white gold to resemble platinum.
Retail Jewelers of America (RJA): A national trade organization formed in 1957. Its purpose is to promote the general welfare of the retail jewelry industry. The RJA also sponsors and organizes national jewelry trade shows.
Rhinestone: Commonly the colorless lead-glass brilliant-cut imitation of diamond. The name originally was given to the colorless quartz pebbles from the Rhine River Valley.
Rock crystal: Transparent colorless quartz sometimes referred to as “Herkimer diamonds.”
Rose cut: An early style of cutting diamonds, probably originated in India. The base (back) is usually flat and the top (front) is slightly dome-shaped and covered with a varied number of triangular facets that terminate in a point, much like a shallow sided pyramid.
Rouge: Jewelers rouge (Iron oxide), a buffing compound for polishing gold.
Rough diamond: A diamond in its natural, uncut or unpolished state.
Ruby: The red variety of corundum. Intense, medium to medium dark purplish red (pigeon’s blood) is best, intense red is fine and dark red is less desirable. The finest specimens come from Burma; less valuable stones are found in Ceylon and Thailand. The birthstone for July.
Sapphire: Any corundum other than ruby, but generally referring to the blue variety. Other colors are pink sapphire, purple sapphire, green sapphire, etc. Best quality blue sapphire comes from Cashmere, fine from Burma, Thailand and Montana, lighter blue from Ceylon. Also found in Australia. The birthstone for September.
Scintillation: Scintillation (flashing or twinkling of light) in gemstones refer to the alternating display of reflections from the polished facets when in motion.
Semiprecious: A vague and misleading classification of all gemstones other than the so-called precious stones; i.e., diamond, ruby, emerald and sapphire. Gemstone is a term used with increasing frequency by professionals to include all cut and polished gem minerals. Consider for example that a poor quality emerald can cost far less than a fine jade.
Setting: Setting or mounting specifically refers to the portion that actually holds the stone as opposed to the rest of the jewelry item it is attached to.
Shallow stone: A diamond on which the pavilion facets are at an angle of less than 39 or 40 degrees to the girdle plane. The less the angle the greater the loss of brilliancy. The diamond will have a very glassy appearance and is usually called a fisheye.
Silver: A white precious metal. It is used in the manufacture of jewelry, silverware, coins, photography, electronics, etc. It is harder than gold, softer than copper, more malleable and ductile than any other metal except gold, and an excellent conductor of heat and electricity. It can be rolled so thin that it transmits light.
Simulated stone: Any substance that imitates a gemstone in appearance.
Single cut: A simple form of cutting for small diamonds. Consists of a table, eight bezel (top) facets, eight pavilion (bottom) facets.
Slightly imperfect: A grade of relative imperfection in a diamond. Abbreviated SI, it is more flawed than very slightly imperfect (VS) but less than imperfect (I).
Solitaire: A ring containing a single center diamond, with or without small diamonds in the shank.
Spread stone: A diamond that has been cut with a large table and a thin crown, to retain greater weight than is possible by using ideal proportions. Also called a swindle-cut or fish eye because the larger diameter suggests more weight than it actually has.
Star facets: The eight triangular facets that bound the table of a round brilliant-cut diamond between the main bezel facets.
Sterling silver: A metallic alloy consisting of 92 1/2% silver and 7 1/2% copper. Sterling silver is usually stamped sterling or 925. The word sterling is derived from Easterling, the name of a 20th-century group of German traders who paid for merchandise with a silver coin, the content of which they rigidly controlled at a time when debasement of coins was common.
Synthetic stone: A reproduction of a stone that has the same physical, optical and chemical properties as the genuine stone it reproduces.
Table: The large facet that caps the crown of a polished diamond.
Tanzanite: Tanzanite was first introduced in 1969 and is found only in a relative small, approximately, five square mile area near the Kilimanjaro Airport in Tanzania. Tanzanite comes in various shades of violet-blue. The less expensive colors range toward violet, a light purplish blue. The best and more expensive colors are a rich deep blue with just a hint of violet. Birthstone for December.
Topaz: A gemstone best known for its beautiful transparent yellow-brown color, also very popular in pink, light blue and reddish-brown colors. Sources; Brazil, Ceylon, California, Maine, Colorado and elsewhere. One of the birthstones for November.
Tourmaline: A gem best known for its green and pink stones. Sources; Brazil, Ceylon, Madagascar, California, Maine and elsewhere. One of the birthstones for October.
Treated (altered) diamond: A diamond that has been coated, laser drilled, filled or otherwise treated to improve or alter its color or appearance.
Very slightly imperfect: A clarity grade between very, very slightly imperfect and slightly imperfect. Abbreviated as VS.
Very, very slightly imperfect: The imperfection grade that is just below flawless. Abbreviated as VVS.
Zirconia, cubic: A man-made material without a natural counterpart that can be used as a diamond substitute. It has a 2.15 refractive index and a hardness of about 8 1/2. Was originally manufactured in Russia, Switzerland and Cambridge, Massachusetts.