A B C  Dictionary of terms    

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A

A.G.S. - The American Gem Society, or A.G.S., was founded and is supported by about 1,000 high end jewelers. After the G.I.A., the A.G.S. is recognized as one of the top gemstone grading organizations. The A.G.S. has developed a commercial cut grading system that has been rapidly gaining popularity and acceptance in the valuation of diamonds. At this time the G.I.A does not endorse the grading of cut as a reliable means of valuing diamonds.

Akoya Pearls - Cultured pearls, typically of white body color, known for their high luster and uniform roundness, mainly cultivated in Japan. Akoyas are very rarely over 10 mm.

Appraisals - Any appraiser should hold a diploma as a gemologist. All appraisals should identify the type of stones and metals, measurements and weights of stones, listing of color, clarity, cut quality blemishes and treatments, type of settings for jewelry.

Assembled stones - Composites of colored stones and glass or a cheaper grade of similar color stone. Called doublets or triplets, with full disclosure, this is a good way to have the beauty of a ruby, emerald or tanzanite at a fraction of the price.


B

Baguettes - A rectangular cut stone with squared corners.

Bar setting - A variation on the channel setting, usually used for wedding bands or designer rings. In the bar setting, thin metal bars are placed between each gemstone on a band to hold them securely in place. This design protects the girdle of the gemstones, holds them more securely than a prong setting, and offers a smooth, sleek appearance. Bar and channel settings typically cost more than prong settings.

Baroque shape pearls - Technically, any pearl that is not round, with a symmetrical, or asymmetrical shape. Baroque shape pearls can be either fresh or saltwater, and are known for deep, rich pools of color. More common than round pearls, baroque shape pearls are generally more affordable, yet can make beautiful, unique jewelry pieces.

Bearding - Very small feather cracks or fractures typically occurring along the girdle of a diamond.

Beeswax - All pearls are tumble cleaned during processing. Occasionally, beeswax is added to the salt-water solution to protect and add luster to the pearls. The process is not permanent and should be thoroughly disclosed on the bill of sale.

Beryl - The mineral composition of emerald, aquamarine, morganite, goshenite.

Bezel - Originally, the bezel of a watch was the glass ring that the watch glass was pressed into to hold it in place. Now, the bezel is also known as the outer ring of the case that can be used for a number of functions such as roman numeral time indicators or diving timers.

Bezel facets - Also called kite facets, because of their shape, bezel facets are cut along the crown, or top, of the diamond or gemstone.

Bezel setting - Holds a diamond or gemstone in place at the girdle by a thin strip of metal that is soldered onto the band. The bezel setting can either create a smooth, flush, appearance, or leave the gem's crown exposed for extra drama. The bezel is also designed to allow maximum light shine through the stone from the bottom, so you get the most protection while still showcasing the brilliance of the stone.

Bill of sale - Or sales receipt. This is one of the most important documents for your gemstone purchases. On it should appear all vendor guarantees, claims of authenticity of a gemstone or pearl and full disclosure of all treatments and enhancements.

Blemish - Any flaw, spot, scratch or cut that appears on the surface of a gemstone.

Body color - The basic color of a pearl. White, cream, black, etc.. Always consider the overtones, orient and luster when evaluating a pearls color.

Brilliance - The amount of light allowed to reflect from inside the diamond or gemstone based on the quality of its cut.

Brilliant cut - Can be any shape gemstone, but must have 57 or 58 facet cuts.

Bruted girdle - A girdle cut that leaves the girdle with a frostlike appearance.


C

Cabochon - A gemstone cut that creates a dome shape. This cut is often seen in opal, turquoise, and star rubies and sapphires.

Carats - One of the 4 C's, carats are a metric system of measurement for gemstones where one carat equals 200 milligrams, or 0.2 grams. Each carat is divided into 100 points, so a 75 point stone is ¾ of 1 carat, a 50 point is ½ carat, etc. Note that gemstones can only be weighed for certification when un-mounted.

Center stone - A large stone in a piece of jewelry surrounded by smaller accent stones. This large stone can also be called the solitaire.

Certificate - The official grading report for diamonds and gemstones. Certificates can come from any of the major gemstone laboratories, the best being the G.I.A. and the A.G.S. The certificate will list all the major quality factors (4 c's). However, the G.I.A. will not include a cut grading on their certificates, while the A.G.S will. Whether grading the cut is pertinent, or even possible, or not is the subject of current debate. You should have ½ carat diamonds certified if the clarity is VS or higher. ¾ carat stones should be certified at SI and up, and 1 carat, above I1 clarity.

Ceylon cut - Another term for Mixed cut.

Channel setting - Two strips of metal hold the gemstone in place by creating a channel for the stone. Unlike the bar setting, channel set stones have no metal between the stones. This is a great setting for active people as the stones are protected from snags and bumps.

Choker - Pearl strands measuring 16" inches.

Central Gem Laboratory - A lab in Japan that specializes in pearl evaluation and reports.

Chalky luster - A term for defining bad luster in pearls. It usually indicates thin nacre, and you'd do better to buy imitation pearls with nice shine than real pearls with chalky luster.

Chronograph - A stopwatch function on a watch that can be started, stopped and reset independently from the normal watch works.

Clarity - One of the 4 c's, clarity is the degree to which a gemstone is free from flaws. A clarity scale has been designed to grade flaws in valuing gemstones. For diamonds, the clarity scale runs from FL (flawless) where there are no internal or external flaws, to I3, with many imperfections clearly visible to the naked eye. A ten-power loupe is required by the FTC to accurately examine a diamond for clarity.

Clarity enhanced - A broad term for gemstones that covers many different treatments or procedures that remove or diminish flaws, thereby enhancing the clarity. Always ask your jeweler what clarity enhancements have been performed on the gemstones you are purchasing, and to state them on your bill of sale.

Clouds - A type of inclusion in gemstones that usually a cluster of tiny inclusions that create a milky appearance and can greatly affect value.

Cluster setting - A group of small stones typically set surrounding a large center stone.

Color - One of the 4 c's, color means different things for different stones. In diamonds, the ideal color is D colorless and runs through the alphabet to Z yellow. For colored stones, on the other hand, each type has a very complex grading system (see our color stone guides for a particular type) Color, of course, is one of the most important value factors for all gemstones.

Color purity - The term used for judging and determining the ideal hue for colored stones.

Color zoning - Patches of uneven color in colored stones that detract from pure dispersion and uniformity of color.

Comfort fit - A term for ring design where the edges are smoothed to a round surface for maximum comfort.

Complication - Any added feature or mechanism added to a watch. The most common complications are calendars, chronographs and alarms.

Corundum - The mineral composition that makes up the ruby and sapphire family of gemstones.

Crown - The upper facets of the diamond, above the girdle, leading up to the table.

Crown height - A measurement in proportion to the pavilion depth. One must be judged against the other to determine proper symmetry.

Crystal - The glass cover of a watch face. Crystals can be made of glass, plexiglass, or in the best quality, a mineral glass like sapphire.

Crystals - A solid mineral deposit in many gemstones that blocks color dispersion when severe.

Culet - The point at the bottom of the diamonds pavilion.

Cultured pearls - A process of cultivating pearls by inserting a mother of pearl irritant into an oyster or other mollusk. Although amazingly beautiful specimens are readily available, cultured pearls will typically have thinner nacre and lack the orient that make natural pearls so lustrous.

Cushion - A square or rectangular cut gemstone with curved edges.

Cut - One of the most important of the 4 c's, and the hardest to judge. The cut is the geometric proportions of a gemstone that allows the inner fire to shine through. Cut is graded from Ideal to Poor and will be stated as such on the gemstone's certificate.