Jewelry A to Z


A

Abraided Culet

A chipped or scratched culet. It can be caused by contact with another diamond. Chipping can occur during setting as well.

(AGS) American Gem Society

Professional organization formed in 1934 by several independent jewelers and the founder of the Gemological Institute of America (GIA). The AGS developed the cut grade of a diamond.

Anneal

A process of heating metal which has become compact and brittle. The heating removes the brittleness and renders the metal soft and malleable, so it can be worked.

Antwerp, Belgium

A diamond trading center where approximately 85% of the world’s diamonds pass through either in rough or cut stones

Appraisal

A monetary evaluation.

Argentium Silver

Is a modern sterling silver alloy which modifies the traditional sterling silver alloy (92.5% silver + 7.5% copper) by replacing some of the copper with the metalloid germanium.


B

Baguette

A rectangular cut stone with squared corners.

Bail

A finding, connected to pendants or stones worn as pendants to accommodate a chain, cord or thong.

Base Metal

Any non precious metal.

Basket Setting

A fancy setting of various shapes with numerous side piercings that provide a basket work or lacy appearance.

Bearding

Small feather-like cracks along the girdle of a diamond. Often an indication that the cutter went too fast.

Bench Jeweler

An artisan who utilizes a combination of jewelry-making skills to make and repair jewelry.

Bezel

Outer ring of a watch case, or a rim of metal around a gemstone.

Bezel Setting

A type of stone setting using a bezel, not prongs

Blemish

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

Brass

An alloy metal composed of various proportions of copper and zinc- an average formula is 65 parts copper and 35 parts zinc.

Brilliance

The intensity and amount of light reflecting from inside a diamond or gemstone.

Brilliant

A type of cutting, used especially on diamonds with 58 facets, and also, now used as a synonym for a brilliant – cut diamond.

Burnisher

A tool for polishing metal by burnishing (by rubbing and pressing it with the steel).

Burnout Furnace

A gas or electrically powered furnace used to eliminate, by burning out, the wax from investment molds.


C

Cabochon

A gemstone cut that creates a dome without facets.

Carat

One of the "Four Cs". Metric unit of weight for diamonds and gemstones. One carat equals 200 milligrams or 0.2 grams. Not to be confused with Karat which is a percentage of purity of gold.

Casting

A process for forming an object by pouring melted metal into a hollow mold; often used for duplicating a piece of jewelry, using the original piece as a pattern for making the mold.

Channel Setting

A type of setting often used in mounting a number of small stones of uniform size in a row, as in a diamond wedding ring.

Chasing

A highly skilled and ancient art of decorating metal with figures or ornamental patterns, which may be either raised or indented.

Clarity

One of the "Four Cs". Measures the degree to which a gemstone is free from flaws. A clarity scale is used to grade flaws in gemstones. The GIA 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. As an example, Mica has a perfect cleavage in one direction.

Cloisonné

A type of decoration for enameled metal-ware, consisting of narrow thin strips of metal soldered in the form of designs to the surface of a piece of ware, the spaces enclosed by the little metal walls filled with different colors of enamel.

Cloud

Group of tiny white inclusions in a diamond, considered a flaw.

Color

One of the "Four Cs". In diamonds, the GIA color scale ranges from D (colorless) to Z (yellow). In colored gemstones, the scale may differ widely depending on the type of stone.

Comfort Fit

Ring design in which the edges of the shank are rounded for maximum comfort. Often found in gents wedding rings.

Copper

A reddish metallic element used in the pure form as a conductor of electricity, also in enamel dial bases, as an alloying element in sterling silver, karat golds, brasses, bell metals, bronzes and other alloys.

Crown

The facets or portions of a gemstone located above the girdle, and below the table or top of a gemstone.

Culet

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

Cultured Pearl

Pearls created by the artificial introduction of an irritant into an oyster or other mollusk.

Cut

One of the "Four Cs". 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. It is what makes a diamond or gemstone sparkle.


D

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.

Diamond

From Old French diamant, which derives from the Latin adamas, “unyielding”. A mineral composed of pure carbon, the hardest of all known substances and a valued gem found in many colors.

DiamondLite

Instrument for color grading diamonds using visual comparisons to master diamonds. Trademark, Gemological Institute of America. It produces close to natural sun light.

Dispersion

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


E

eElectroplating

Process of covering metal articles with a film of other metals.

Emerald Cut

Step cut style of cutting for a gemstone (most often rectangular) whose corners have been cut off. It is rectangular in shape.

Engraving

The art of cutting designs in any substance; in the jewelry trades, particularly made of the precious metals.

Etching

A process for producing designs on metal by using acid, the design is scratched through a coating of wax or varnish on the article, exposing the surfaces of the metal, and acid is applied to eat into the metal to form the design in etching.

Eye-clean

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


F

Facet

Flat, polished surface on a gemstone.

Faceted girdle

Girdle that has been cut with facets, not as good as a smooth or polished girdle.

Fancy Shapes

Any gemstone shape other than round.

Feather

A word describing a crack (flaw) in a gem stone.

Findings

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

Fire

Refers to the sparkles or flashes of spectral colors emitted from diamonds and other gemstones.

Fire Scale

Discoloration of copper alloys when heated in air. In the case of sterling silver this discoloration is extremely difficult to remove.

Flaw

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

Flawless

Lack of flaws in a gemstone under 10x magnification.

Fluorescence

Luminescence that appears when certain diamonds are exposed to ultraviolet light, commonly a tint of blue

Fracture

Cracks or feathers in a gemstone.

Full Cut

Gemstone with 58 facets, including the culet.


G

Gem

A stone cut and polished for use in jewelry, which fulfills the requirements for beauty, durability and rarity.

Gemologist

Gemstone specialist trained in gem identification, grading and appraising.

Gemology

Science and study of gemstones.

Gemstone

A naturally occurring mineral found in the rocks of the earth, the chemical composition and internal atomic structure of which make it suitable for jewelry use: color, clarity, hardness, rarity and availability.

(GIA) Gemological Institute of America

Created the color and clarity grading system in 1954 most commonly used today.

Girdle

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

Gold

A chemical element with the symbol Au. It is a highly sought-after precious metal which has been used as money, a store of value and in jewelry since the beginning of recorded history.

Gold filled

Metal covered by a thin layer of gold that is at least 10k and 1/20th of the total weight of the piece.

Gold plated

Virtually the same as gold filled, except gold plated items may have a layer of gold that is less than 1/20th of the total weight of the piece.

Goldsmith

A metalworker who specializes in working with gold and other precious metals, usually in modern times to make jewelry.

Grading

Valuing a diamond using color and clarity standards.


H

Head

Often called a crown. It holds the stone

Heated Stone

A stone that has been treated by heat to change its color at the mine or after cutting; often in electric ovens with stones embedded in sand.


I

Imperfection

Term used to refer to internal or external characteristics of a gemstone.

Inclusion

Visible internal flaws in a gemstone, including fractures, crystalling abnormalities, and foreign objects.

Irradiation

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


J

Jeweler

A merchant who sells diamonds, other gemstones and jewelry.


K

Karat

Standard measure of gold purity. One karat is 1/24th pure. Not to be confused with carat which is a unit of weight, pure gold is 24 Karat.


L

Lapidary

A person who cuts and polishes gems except, in trade usage, diamonds.

Laser Drilling

Technique used to enhance a stone's clarity by drilling a hole in it with a laser

Leakage

Light leaving, or escaping, through the facets of fashioned gemstone, which is worse with poorly cut stones.

Leveridge Gauge

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

Lost Cast Waxing

A process of casting whereby a wax model is encased in an investment similar to plastic.

Loupe

Small magnifying glass, used for analyzing gem stones, usually 10 power.

Luster

The appearance of a material's surface.


M

Mandrel

A steel rod slightly tapered, used as an anvil for forming rings by blows with the rawhide mallet.

Marquise

A shape with both ends sharpened to points.

Master Stones

A set of diamonds used to grade the color of other diamonds.

Metallurgy

The art and science of extracting metals from their ores and preparing them for use by the manufacturer, who fashions them into finished articles.

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. Talc is 1, diamond is 10.

Mounting

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


N

Nacre

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

Nickel Silver

Or German silver. So called because of some color resemblance to the precious white metal; not because of any silver content.


O

Off Color

A stone showing any semblance of undesirable color.

Oiling

Temporary treatment used to enhance the color of a gemstone, often used on Emeralds.

Opera length

A strand of pearls 32 inches.

Ounce Troy

A unit of Troy weight, long used for weighing precious metals. The ounce contains 20 penny-weights each of 24 grains.

Oxidation

The forming of an oxide, as the copper in sterling silver or a karat gold alloy combining, through heat, with oxygen and forming a copper oxide.


P

Pallaver

An alloy developed and trademarked by Adair Jewelers of Missoula MT. That is comprised of palladium, silver, germanium, and other metals.

Palladium

A platinum group metal mined in Eastern Montana at the Stillwater Mine, among other places.

Pave (pah-vay)

Style of setting small stones as close together as possible using shared prongs.

Pavilion

The portion of a gemstone located below the girdle.

Pennyweight

A unit of Troy weight, long used for weighing precious metals.

Platinum

Precious metal that is harder than gold, and more rare. Platinum does not tarnish and is hypo-allergenic. It is also sourced at the Stillwater mine in Montana.

Platinum Group

The six metallic elements, platinum, palladium, iridium, osmium, rhodium and ruthenium.

Plot

Diagram of a gemstone's clarity characteristics. Generally done as part of an appraisal.

Point

One-one hundredth (0.01) of a carat.

Princess Length

A strand of pearls 18 inches.

Princess Cut

A type of square cut primarily used in diamonds.

Prong

A metal piece bent around the girdle of a gemstone to hold it in place.

Proportion

Mathematical representation of a gemstone's overall length to width.


Q

Quartz

Silicon dioxide, one of the commonest of all minerals. It crystallizes in a the hexagonal system. When its purple it is called Amethyst, when yellow Citrine.


R

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.

Rope Strand

A strand of pearls 40 inches in length.

Rough

An uncut or unpolished diamond or gemstone.


S

Scintillation

Is the sparkle effect you see when a diamond, the light or the observer moves. GIA defines scintillation as “flashes of light reflected from the crown”.

Semi-precious

The second and largest of the three categories into which gemstones have been divided by traditional usage. Examples are tanzanite, red tourmaline, green garnet, golden topaz, amethyst and chrysoprase.

Setting

Method of holding gemstones in place (i.e., prongs, bezels, or pave)

Shank

Part of the ring that encircles the finger.

Silver

Is a chemical element with the symbol "Ag". A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal.

Single Cut

A simple form of cutting that has a table, approximately 16 facets and rarely a culet. Usually found in older small diamonds.

Soldering

Uniting pieces of metal by melting between them another kind of metal.

Solitaire

Ring containing a single diamond or gemstone.

Symmetry

Uniformity of a gemstone's cut. The more symmetrical, the more brilliance.

Synthetic stone

"Man-made" gemstone grown in a lab, which duplicates a natural stone.


T

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.

Tolkowsky, Marcel

Mathematician that defined the proportions necessary for maximum brilliance from a round diamond brilliant cut in 1918.


U

Ultrasonic

Cleaning device for jewelry that removes dirt through the use of ultrasonic waves.


W

White Gold: Usually, an alloy of gold, copper, nickel and zinc.

Y

Yellow Gold: See Gold