Glossary
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- AGS
- The American Gem Society; One of the foremost authorities on grading diamonds.
- AGTA
- The American Gem Trade Association. A top authority on gemstone testing and identification.
- Alloy
- When precious metals like Gold and Platinum are mixed with other metals to strengthen them and change their properties, the result is called an Alloy. Platinum is often mixed with ruthenium or iridium, to produce 950 or 900 Platinum. Gold is mixed with zinc, copper, nickel and/or silver to produce different Gold alloys.
- Anneal
- A treatment process of heating and slow cooling of colored gemstones and metals.
- Appraisal
- An Appraisal, unlike a grading report, appraises the value of your entire piece of jewelry. This record includes a photograph of the piece, a description, as well as cut, color, clarity, and carat information about your diamond. This report can be used with your insurance agent to get insurance rates, as well as establish your retail replacement value, incase of loss, damage or theft.
- Average Girdle Diameter
- The average measurement of the longest and shortest diameter on a round shaped diamond.
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- Baguette
- Small Rectangular Diamonds that are often used as accent stones.
- Bar setting
- Individual metal bars are used to hold the gemstones in a setting. Link to picture.A ring which is the same width through out the entire circumference.
- Baroque Pearl
- A shape of pearl- a freeform shape lacking symmetry.
- Bezel setting
- A metal rim holds the diamond in place by its girdle.
- Birthstones
- The traditional gemstones associated with each birth month are
- January: Garnet
- February: Amethyst
- March: Aquamarine
- April: Diamond
- May: Emerald
- June: Pearl, Alexandrite
- July: Ruby
- August: Peridot
- September: Sapphire
- October: Opal, Pink Tourmaline
- November: Yellow Topaz, Citrine
- December: Blue Topaz, Turquoise, Zircon
- Blemish
- A clarity characteristic confined to the surface of a gemstone.
- Blister Pearl
- A 'pearl' that grows on the interior surface of a mollusk's shell.
- Brilliance
- The amount of white light seen within a diamond. Brilliance is affected by the cut of the stone.
- Brilliant cut
- A style of cut that creates triangular and kite shaped facets.
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- Calcium Carbonate
- The main mineral component of a pearl's nacre (outer layer).
- Carat or Carat Weight
- A unit of measurement to evaluate the weight of gemstones. One Carat is equivalent to 200 milligrams or 0.2 grams.
- Center stone
- The central dominant stone in a piece of jewelry with multiple stones. This stone is usually the largest and most prominent.
- Certificate
- See grading Report
- Channel setting
- Metal rails that hold the diamond in a setting.
- Chip
- A very small clarity characteristic that appears like a cavity under high power magnification.
- Clarity
- Clarity is the relative freedom of inclusions and blemishes within a diamond. There are 11 Clarity grades, ranging from Flawless to Included.
- Clarity Characteristics
- Any visible blemishes or inclusions that can be seen in gemstones under 10X magnification.
- Cleavage
- A plane of atomic weakness resulting from the atomic arrangement within a crystal. Labeled a feather when seen in a diamond.
- Cloud
- A cluster of microscopic inclusions inside a stone.
- Color
- One of the traits used in grading your diamond. Color is graded on a scale from D (colorless) to Z.
- Comfort fit
- In ring bands, the inside of a ring shank is curved to provide a more comfortable wear.
- Corundum
- The mineral species which includes rubies and sapphires.
- Crown
- The portion of a faceted gem above the girdle.
- Culet
- The location at the bottom of a faceted gemstone where the pavilion facets meet. The culet may or may not be faceted.
- Cultured Pearls
- A pearl that formed as a result of human intervention. A small irritant made with a mother-of-pearl bead or mantle tissue is inserted into the mollusk to induce pearl production. Kokichi Mikimoto was credited for perfecting the nucleation process.
- Cut
- Cut refers to a stone's shape, design and faceting style. The beauty of a stone is highly dependent on how well it is cut.
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- Depth
- The height of a diamond measured from the table to culet.
- Depth Percentage
- The depth of the diamond expressed as a percentage of the Average Girdle Diameter (or Width for fancy shapes). When the depth percentage is too deep or shallow it will affect the beauty of the stone.
- Diameter
- The width of a round shaped gemstone.
- Diamond
- A precious gemstone made of highly compressed carbon deposits. Diamond is the hardest known substance.
- Dimensions
- The width, length, and depth measurements of a gemstone.
- Dispersion
- The splitting of white light into spectral colors as a result of refraction; Commonly referred to as fire in the trade.
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- EGL
- European Gemological Laboratory.
- Enhancements
- A human controlled process used to improve the apparent beauty of a gemstone. Common enhancement processes include heating and fracture filling.
- Emerald-cut diamond
- A style of cutting that creates step-cut facets radiating from the table.
- Extra facet
- Small facets added to remove clarity characteristics or correct minor cutting discrepancies.
- Eye clean
- A term used when a diamond has no imperfections visible to the unaided eye.
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- Facet
- The flat polished surfaces of a diamond. A round brilliant cut has 57 or 58 facets.
- Fancy Shape
- Diamonds of any shape other than round. These include Princess, Pear, Oval, Heart, Trilliant and many other shapes.
- Feathers
- A clarity characteristic similar to the appearance of a feather. May occur naturally or from the result of mining and/or cutting processes.
- Finish
- Finish Refers to the attention of detail achieved by the diamond cutter. This includes the polish and symmetry aspects of cut.
- Fire
- See Dispersion
- Fluorescence
- A bluish glow which emanates from some diamonds when exposed to ultraviolet light. Strong florescence is not desirable, but small amounts will not detract from the appearance of a stone.
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- Gemstone Color
- The color scale used to define the color of a gemstone in terms of hue, tone and saturation.
- GIA
- The Gemological Institute of America. Recognized as the top authoritie on diamond grading.
- Girdle
- The band around the widest part of a diamond, where a setting attaches to a stone.
- Gold
- A precious metal which has been used in jewelry for centuries. It is a malleable metal which is usually mixed with other metals to give more strength. Gold will never tarnish, rust or corrode.
- Grade
- Diamonds are sent to independent gem grading laboratories to be objectively graded against a master set of stones to define the quality of the diamond. These grades on the 4Cs are listed in the Grading Report.
- Grading Report
- A Grading Report or Certificate is a report compiled by an independent laboratory assessing many different qualities of your stone. This report assures that the diamond you have is the one you paid for, and also serves as a measure of quality.
- Graining
- A clarity characteristic resulting from irregularities in the atomic arrangement of a growing crystal; Appears as faint single line or groups of lines.
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- Head
- The metal (usually platinum) basket which holds the center stone or solitaire in place with prongs. This determines what shape and size diamond the setting can hold.
- Heart-shaped diamond
- A fancy cut diamond which is shaped like a heart.
- Hue
- A term used to describe the pure spectral sensation of color; Red, orange, yellow, green, etc.
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- Ideal Cut
- A diamond cut to utmost precision to maximize brilliance and fire. In 1919, Marcel Tolkowsky calculated a set of measurements that would produce a Round Brilliant cut diamond with the best balance of Brilliance, Dispersion and Scintillation. The AGS now defines an Ideal Cut Diamond, as any diamond which has cut proportions close to that of the Tolkowsky's Ideal Cut.
- Inclusion
- Any clarity characteristic found within or penetrating into a faceted gemstone.
- IGL
- Independent Gemological Laboratories.
- IGI
- The International Gemological Institute
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- Karat
- The measurement of the purity of gold. 24 karat gold is pure gold, while 12 karat gold is 50% gold and 50% alloy.
- Knot
- An included crystal that is partially exposed on the surface of a faceted diamond.
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- Length to width ratio
- A ratio between the length and width of a fancy shaped diamond. Used to determine the appeal of a fancy shape cut.
- Loupe
- A handheld magnifier used by jewelers to observe clarity characteristics or cut features of a gem.
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- Marquise-cut diamond
- A Fancy Cut Diamond Shape that is elongated with pointy ends, inspired by the grin of the Marquise de Pompadour.
- Millimeter
- A unit of measurement equivalent to 0.1cm.
- Mohs hardness scale
- A scale of relevant Hardness, where 10 is the hardest and 1 is the softest. The Diamond ranks 10 on the Mohs Scale.
- Mother of Pearl
- The iridescent lining of the inside of a mollusk's shell. Often used as decorative pieces, such as buttons.
- Mounting (or setting)
- The portion of a piece of jewelry where gemstones are set.
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- Nacre
- The crystalline substance secreted by a mollusk to form a pearl. The exterior layer of a cultured pearl.
- Natural Pearl
- A pearl that formed naturally without human intervention.
- NGL
- Northwest Gemological Laboratory
- Natural
- Original surface of a rough diamond found by the girdle of a faceted stone.
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- Oval diamond
- A fancy diamond shape based on an elongated round cut diamond.
- Overtone
- A secondary color that overlays the body color of a pearl, usually rose, green or blue in color.
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- Patina
- The gentle sheen which develops on the surface of platinum jewelry through continued wear. This unique look is preferred by many who wear platinum.
- Pave
- A setting style which involves setting many small diamonds very close together which gives the impression of a ring paved in diamonds..
- Pavilion
- The lower part of the diamond, located below the girdle.
- Pear-shaped diamond
- A Fancy shape diamond that is teardrop shaped. Based on a round shaped diamond, this shape has a single point.
- Pinpoint
- A microscopic included crystal.
- Platinum
- A precious metal used in jewelry. Platinum is naturally white, and is favored for many ring settings because of its strength and timeless beauty.
- Point
- A unit of measure for weight, a point is .01 carats. A diamond which is .75 carats is 75 points.
- Polish
- This grading defines how smoothly the facets of a diamond have been polished after they are cut. A smooth polish greatly enhances a diamond's brilliance, while a poor finish can detract from an otherwise beautiful stone.
- Princess-cut diamond
- The most popular diamond cut after the round brilliant cut. The princess cut is a square or rectangular modified brilliant cut.
- Prong
- A prong setting frequently uses 4 or 6 prongs to hold a diamond in place. Each metal prong is individually pushed into place to hold the diamond securely.
- Proportion
- The angles, size and placement of facets on a gemstone; Used to evaluate the cut of a diamond.
- Push earring back (Tension or Friction Post)
- A Push Earring back has tension rings which work with an indentation on the earring post to hold the earring securely in place.
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- Radiant-cut diamond
- A square or rectangular modified shaped diamond with trimmed corners.
- Ring size
- A measurement of finger size, generally found by measuring both the finger that the ring will be worn on, as well as the knuckle that the ring must slip over. Ring sizes are generally between 4 and 13, with 6 as the average woman's ring size.
- Rhodium plating
- A platinum group metal used to coat white gold to produce a hard bright white finish.
- Rose Gold
- All gold used for jewelry is mixed with other metals to increase its strength (see Alloy) Rose Gold is a reddish toned gold which is created by adding slightly more copper to the alloy.
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- Scintillation
- Small sparkle of lights that reflect from a diamond.
- Screw earring back
- These earring backs give extra protection for very expensive earrings. The threaded post and screw backs hold the earrings securely in place.
- Setting
- See mounting
- Shank
- The part of a ring which goes around the finger.
- Shape
- The face up outline of a stone after it has been cut. Common Shapes are the round, princess (square) or oval, but diamonds take on many forms, including hearts, pears, or triangles (trilliant)
- Side stone
- A gemstone or diamond which is mounted alongside the center gem or diamond.
- Single Cut
- A small diamond which has only 17 or 18 facets instead of the usual 57 or 58. These tiny diamonds are usually used for pave settings or other jewelry that involves many small diamonds.
- Skin Oil
- Diamonds have an affinity for oil. Skin oil on the diamond will dull the appearance.
- Solitaire
- A single stone diamond ring. The classic engagement ring.
- Step Cut
- A type of cut which has rectangular facets, most commonly seen in Emerald cut diamonds. These broad rectangular facets
- Symmetry
- This grading defines the accuracy of alignment, size and shape of facets.
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- Table
- The largest facet of a diamond, located at the top of the stone.
- Table percentage
- The size of the table expressed as a percentage of the Average Girdle Diameter (or width on a fancy shape). This percentage is an indication of the quality of a diamond's cut.
- Tennis Bracelet
- A trade term used to describe an inline diamond bracelet.
- Tension Post
- See Push Earring Back
- Tone
- The lightness to darkness of a color's hue.
- Trilliant Cut
- A triangular shaped diamond.
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- Ultrasonic
- An Ultrasonic Cleaner is a device used by jewelers to clean jewelry using ultrasonic waves. This method loosens dirt most effectively, and small home units can also be found.
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- White Gold
- A white colored gold alloy. Made of Gold, Nickel, Copper and Zinc.
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- Yellow gold
- Pure gold has a rich golden yellow color, and the color of gold used for jewelry is dependent on the metals used in the alloy.
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