ABRADED CULET
A chipped or scratched culet. Can be caused by contact with another diamond.

ABRASION
A bruise or scratch on the surface of a stone.

APPRIASAL
A monetary evaluation, usually performed for insurance purposes by a gemologist. Appraisals should describe the piece in detail, including color, clarity, proportions, stone sizes, flaws and other distinguishing characteristics.

BAGUETTE
A rectangular cut stone with squared corners.

BASE METAL
A common metal like copper or nickel.

BEARDING
Small feather-like cracks along the girdle of a diamond.

BEZEL SETTING
A circle of metal around the girdle of the stone to set the stone securely and to protect the edge (girdle) of the stone.

BLEMISH
A flaw, spot or scratch on the surface of a gemstone.

BRILLIANT CUT
Any round cut stone, most popular cut for diamonds, with 58 facets polished on the stone based on a mathematical calculation to give a stone the most brilliance.

CABOCHON CUT
The smooth domed rounded polish used on colored gemstones where the reflection of light is not crucial. The backside of the stone is usually flat.

CARAT
The term describing the weight of a gemstone. ( Not to be confused with KARAT, the purity of gold.) The word CARAT comes from the CARAB SEEDS (Ceratonia siliqua). The seeds of the Carob tree were used on precision scales as units of weight for small quantities of precious gemstones because of their uniform size. One carat is equal to 200 milligrams, 0.2 grams, or 0.007 ounces (avoirdupois). Five carats equals 1 gram, and 141.7 carats equals 1 ounce. There are 100 points in 1 carat. For instance, 0.25 carats is generally expressed as 25 points, or 1/4 of a carat.

CASTING
Pouring liquefied metal usually into a plaster mold to fill void to create the desired shape. Casting has been for over 6000 years.

CLARITY
Measures the degree to which a gemstone is free from flaws. A clarity scale is used to grade flaws in gemstones. The scale ranges from FL (Flawless) where there are no visible internal or external flaws to I3, where many imperfections are visible to the naked eye.

CLEAVAGE
Tendency of a crystalline material to break in certain directions, often along a grain or crystal face.

CLOISONNE
Where colored glass powder is placed in tiny wire cells called cloisons, and after being fired in a kiln, the glass melts into a hard surface. First developed in the Near East, it spread to the Byzantine Empire and from there along the Silk Route to China.

COLOR
In diamonds, the color scale ranges from D (colorless) to Z (yellow). In colored gemstones, the grading scale differs widely depending on the type of stone.

COLORED GEMSTONES
All gemstones other than diamonds.

COLOR GRADING
Valuing a diamond using color graded master stones.

CLOUD
Group of tiny white inclusions in a diamond.

CROWN
The facets or portions of a gemstone located above the girdle.

CULET
A small polished facet located at the sharp point or base of a faceted diamond or gemstone.

CULTURED PEARL
Pearls created by the artificial introduction of a mother-of-pearl irritant into an oyster or other mollusk. Cultured pearls generally have thinner nacre and lack the luster of a natural pearl.

CULTURED
A term used for gemstones that are laboratory grown, that are optically and chemically the same as those found naturally. Or oysters that have been seeded by man to develop pearls that are known as Cultured Pearls.

CUT
Perhaps the most important factor in determining the value of a diamond or gemstone. The cut refers to the geometric proportion that dictates the reflection and refraction of light within a stone.

DEPTH
The distance from a gemstone's table to its culet (top to bottom).

DEPTH PERCENTAGE
The measurement of a gemstone's depth (top to bottom) in relation to its diameter. Depth percentage is primarily responsible for refraction, which produces the fire or sparkle in a gemstone.

DIAMOND
A highly compressed form of carbon, diamond is the hardest marital known.

DIAMOND GAUGE
A mechanical device used to determine the precise measurements of a gemstone.

DISPERSION
The separation of white light into the full color spectrum. Often described as the "fire" or sparkle when discussing diamonds.

EMERALD CUT
A rectangular cut in which two sides are longer than the other two sides. The facets are cut horizontally the length of each side.

ENAMEL
The melting of glass powder to form a colored glass surface.

ENGRAVING
Decorating the surface of metal or gemstone from the front (top) side, by hand or machine.

EYE-CLEAN
Gemstone in which the flaws cannot be seen without a 10x loupe.

FABRICATION
A term used to indicate a piece made by hand, as opposed to a piece that was cast.

FACETING
The cutting of flat faces or plane on a gemstone.

FACETED GIRDLE
Girdle that has been cut with facets.

FANCY COLOR
A term used to describe a diamond with sufficient body color, yellow being the most common. Color in diamonds is rated in intensity from Very Faint to Vivid. Diamonds come in every color.

FANCY CUT
The term used to describe any cut other than the round brilliant of a diamond.

FANCY SHAPE(S)
A gemstone shape other than round.

FAUX
The French word for “fake” or “false”. Used in jewelry to describe glass stones, or beads that emulate genuine stones or pearls. Not to be confused with man made cultured stones or pearls.

FEATHER
Internal flaw (inclusion) that has a feathery appearance.

FINDINGS
Small, pre-fabricated parts of jewelry such as clasps, settings, etc.

FIRE
The sparkles of flashes of spectral colors emitted from diamonds and other gemstones.

FLAW
General term used to refer to internal or external characteristics of a gemstone (i.e., inclusion, fracture, etc)

FLAWLESS
Term used to describe a gemstone that lacks discernable internal or external blemishes when viewed by a gemologist using no less than 10x magnification.

FLUORESENCE
Luminescence that appears when certain diamonds are exposed to ultraviolet light.

FORGING
A hammering process to shape and form gold.

FRACTURE
Cracks, feathers or chips in a gemstone.

FULL CUT
Gemstone with 58 facets.

GEMOLOGIST
Gemstone specialist trained in gem identification, grading and appraising.

GEMOLOGY
Science and study of gemstones.

GIA
Gemological Institute of America. Non-profit organization specializing in grading diamonds and gemstones. Widely held as the premier laboratory for gemological grading.

GIRDLE
The narrow rim around a gemstone separating the crown from the pavilion.

GIRDLE
The edge circumference of a gemstone.

GOLD
AU (from its Latin name aurum) Pure gold is based on 24 parts, known as 24 karat gold. (see “Karat “ for jewelry gold purity).

GOLD ALLOY
A mixture of gold an other metals added to strength to gold in various karat qualities and depending on the other metals, change the color. There is yellow gold, white gold, rose (pink) gold, green gold, and black gold.

GOLD ELECTROPLATE
The electrolytic process of covering a metal base item with a layer of gold.

GOLD FILLED
A layer of gold bonded over a base metal. An example of something marked ”1/20 12K” means 1/20 of the weight of the item is 12-karat gold.

GRANULATION
A technique perfected by the Etruscans around the 7th century B.C. of surface decoration using tiny pure gold balls individually applied to a high karat gold surface. The balls may be arranged in patterns or used in single rows.

HEAD
Portion of a jewelry item that holds the stone.

HAMMERING
To texture or shape gold or silver with small mallets by repeated blows.

HIGH KARAT GOLD
Where gold is at least 20-karat in purity. The higher the karat, the yellowier the gold.

IMPERFECTION
General term used to refer to internal or external characteristics of a gemstone (i.e., inclusion, fracture, etc)

INCLUSION
Foreign material or fractures that are found within a gemstone.

IRRADIATION
Treatment performed on gemstones and even pearls to enhance color.

KARAT
The purity of gold based on 24 parts. 24K or 24 karats is pure gold. 18K is 750 parts gold & 250 parts other metals. 14K is 583 parts gold & 417 parts other metals. 10K is 417 parts gold & 583 parts other metals. In the United States, 10K is the lowest gold as recognized by law. In Europe the make jewelry in 8K.

LASER DRILLING
Technique used to enhance a stone's clarity by allowing for the introduction of bleaching agents or other enhancing agents.

LEAKAGE
Light leaving, or escaping, through the facets of fashioned gemstone.

LEVERIDGE GAUGE
A millimeter gauge used to measure both mounted and unmounted stones.

LOST WAX CASTING
Where the design is made in wax or special plastic. It is covered a special plaster, and the wax or plastic is baked out creating a negative cavity in the plaster. Gold or silver is then poured into this cavity. After the metal has cooled the plaster is removed leaving the casting to be polished and finished.

LOUPE
Small magnifying glass, often held up to the eye or held in the eye socket, used for analyzing gemstones.

LUSTER
The appearance of a material's surface, as determined by the quantity and quality of light reflected.

MALLEABILTY
The ease which metal can be worked through drawing, rolling or stretching. The more the metal is worked the harder it becomes to work. Reheating the metal soften it enough to work it easier.

MARQUISE CUT
A slender cut where it tapers to a point at each end.

MASTER STONES
A color graded set of diamonds used to grade the color of other diamonds.

MATTE FINISH
A dull or muted finish put on by very fine sandpaper or sandblasting.

MILGRAIN
Tiny beads of metal used to decorate bands of metal

MOH's SCALE
Scale used to measure gemstone hardness. Scale ranges from 1 to 10.

MOKUME
From the Japanese word meaning “wood grained”. In jewelry it is a sandwich of metals, often multi-colors of gold that are manipulated to form patterns.

MOUNTING
Method of holding gemstones in place (i.e., prongs, bezels, etc.)

NACRE
Crystalline substance that forms a pearl when secreted by a mollusk in response to an irritant.

OFF COLOR
A stone presenting any semblance of undesirable color.

OILING
A temporary treatment used to enhance the color of a gemstone. (Usually natural emeralds)

OPERA
A strand of pearls 32 inches in length.

PAVE
The technique of setting small diamonds closely together on a metal surface filling it.

PAVILION
The portion of a gemstone located below the girdle.

PEARLS
A natural occurrence where a piece of sand causes an oyster to coat the irritant with nacre, creating a pearl. Oysters that have been seeded by man to develop pearls that are known as Cultured Pearls.

PEAR SHAPE CUT
Cut in a tear drop shape, round at one end and pointed at the other end.

PERCUSSION MARK
Indentation or bruise on the surface of a gemstone caused by contact from a pointed object.

PIT
Indentation on the surface of a diamond or gemstone.

PITINA
A surface discoloration to the metal after it has been exposed to the atmosphere or through a chemical treatment. Some artist use it as an integral part of the surface decoration.
Patinas are liquids that you brush on or soak your items in. They will most frequently give that green color of the statue of liberty. Now a days you can also get them to produce shades of blues, browns, grays and blacks.

PLUMB GOLD
The 1934 stamping act permitted gold content to be up to ½ karat off. This law was amended in the 1970’s to reflect what was stamped in the jewelry. If it was stamped 14K, then it must be at least 14-karat, and not 13 ½ karat.

PLATINUM
Precious metal that is far harder than gold. Platinum does not tarnish and is hypo-allergenic.

PLOT
Diagram of a gemstone's clarity characteristics. Generally performed during an appraisal using magnification.

POINT(S)
Based on a system of 100, one-one hundredth (0.01) of a carat, 1-carat is equal to 100 points. ¼ carat is equal to 25 points.

PRECIOUS METALS
These include silver, gold, platinum, palladium, and rhodium.

PRINCESS CUT
A square cut stone with horizontal facets o the crown (top) and vertical facets on the pavilion (bottom half) to give the stone more brilliance.

PRINCESS
A strand of pearls 18 inches in length.

PRONG SETTING
Where two or more metal wires hold the stone in place. Most common are four or six prong heads used to hold stones in place.

PROPORTION
Mathematical representation of a gemstone's overall symmetry.

RECUTTING
Refinishing a polished stone in order to improve the stone's clarity, proportion or other imperfection.

REFLECTION
Light rebounding off the polished surfaces of a gemstone.

REFRACTION
Bending of light waves. When white light is refracted, a full spectrum of color appears, as in a prism.

RETICULATION
Heating or chemically treating the surface to melt and bubble it to form interesting textures.

ROLLER PRINTING
Running a sheet of metal through a rolling mill along with another element that will then be embossed into the metal.

ROPE
A strand of pearls 40 inches in length.

ROUGH
A term to describe a gemstone as it is naturally found before polishing.

SANDBLASTING
A surface treatment of blasting the metal with tiny sand grains that create a textured or mat finish.

SETTING
Method of holding gemstones in place (i.e., prongs, bezels, etc)

SHANK
Part of the ring that encircles the finger.

SILVER (GERMAN or MEXICAN)
Metals that contain no silver.

SEMI-PRECIOUS
A term that was used to describe any stone that was not ruby, sapphire, or emerald. Today most colored stones are defined as precious.

SINGLE CUT
A simple form of cutting that has a table, approximately 16 facets and rarely a culet.

SIMULATED
A material that is used in place of a real gemstone, but is not the cultured gemstone. IE cubic zirconium is used as a simulated diamond. A diamond grown in a laboratory is a cultured diamond, and is not a simulated diamond.

SOLID GOLD
A term used describe kart gold, rather than a gold plated or gold filled item.

SOLITAIRE
Describes a piece of jewelry with one stone set in it. Usually used to describe a plain engagement ring with the diamond set in a four or six prong head.

STERLING (SILVER)
Sterling is based on a scale of 1000 parts. Jewelry silver is 925 parts silver and 75 parts alloy.

SYMMETRY
Uniformity of a gemstone's cut, including the shape and placement of facets.

SYNTHIC GEMSTONE
"Man-made" gemstone grown in a lab.

TABLE
Largest facet on a gemstone. The table sits atop the crown and allows light to enter and exit, creating the stone's brilliance.

TABLE PERCENTAGE
Diameter of a gemstone divided by the size of the table.

TENSION SETTING
Where a stone is held in place at the girdle by the metal pushing against it. The piece has to be thick enough as not to flex or bend, as the stone would fall out.

TEXTURE
Describing the finish on the metal other than a bright finish.

Tolkowsky, Marcel
Mathematician that defined the proportions necessary for maximum brilliance from a round diamond brilliant cut

ULTRASONIC
A cleaning device for jewelry that removes dirt through the use of ultrasonic waves. Note: Certain gemstones may be damaged by an ultrasonic cleaner.

VERMEIL
A sterling base which is plated with karat gold.

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