Alloy:  A metal made up of a mixture of two or more different metals.  Common examples of alloys include brass (copper and zinc), bronze (a mixture of copper and tin), and pewter (tin with antimony, copper and sometimes lead).
Alluvial deposit:  An accumulation of the sediment deposited by flowing water, such as in a riverbed or delta.
Amber:  Formation of amber goes back millions of years ago - up to 300 million years - when, certain tree resin hardened and fossilized over a long period of time.  Whatever got trapped in the tree resin, go preserved in exactly the same shape to the very finest detail - droplets of air, water, pieces of leaves, flowers, wood from ancients forests, even small living organisms such as insects are still found in amber.  The biggest source of amber comes from Northern Europe's Baltic Sea region.  Used in jewelry making in Europe for ages, as well as a form of currency and even a medicinal stone.
Ammolite:   Ammolite is the modern-day gemstone of ammonite, and because every single gemstone is a fossil, it is regarded as the rarest gem on earth.  The brilliant 70 million year old mineralized fossil ammonite shell this gem comes from is unique to southern Alberta, Canada.  Rare, gem-quality ammolite appears similar to black opal, showing different color combinations when the stone is viewed from different angles. The most common colors range from yellows, oranges to reds and greens. The blues are more rare and hence more expensive.  The Blackfoot Indians believed it would help provide food and used it in bison hunting ceremonies wrapped in a medicine bundle.  In 1981 the International Colored Gemstone Commission recognized this organic gemstone as "Ammolite".  Also see MOROCCAN AMMONITE.
Anti-Clastic Raising:  Hand hammering gold with wooden mallets which causes flat sheets of metal to curl and curve.

Bail:  A Bail is the attachment at the top of a pendant, enabling the pendant to hang from a chain.
Base Metal:  Non-precious metals used as a core for plating and gold-filled items.  A common metal such as brass, copper or nickel are common base metals in jewelry.
Bezel Setting:  A method of seating a stone within a circle of metal to hold it securely, to protect the GIRDLE of the stone, to enhance its appearance, and as part of a design.
Box Chain:  A Box Chain is a chain with wide, square links that form boxes.
Box Clasp:  Has a hollow housing with a groove in which a spring tongue clicks into place to secure the clasp shut.
Brilliant:  A round diamond, the most popular cut for diamonds.  It is based on a mathematical calculation in which 58 facets are placed on a diamond by polishing.  The best stones follow the formula most closely and reflect the most light.
Briolette Cut:  A gemstone or diamond that is cut in a teardrop form.  This type of cut is used in many drops and pendants.
Buttercup:  A buttercup is a six-prong setting, with tall prongs, that resembles a flower.  The setting is scalloped in design.
Byzantine Chain:  A type of chain that has close-fitting links, which create an intricate design and form a tubular chain.

Cabochon:  Polishing a gemstone to a smooth, rounded surface.  Used only for colored gemstones in which the reflection of light is not crucial.  The back of the stone is generally flat.  A faceted cabochon is cut with faceted surfaces around the edge of the stone.
Carat:  Term describing the weight of a gemstone, not to be confused with KARAT.  A carat is 1/140th of an ounce; each carat is further divided into POINTS.
Casting:  Making a model or mold of wax or metal and creating multiple copies of the same item by using the mold repeatedly.
Chasing:  Decorating the front surface of a metal sheet by making tiny indentations with an incising tool.
Chambered Nautilus:  Nautilus pompilius, nautilus are widely recognized shells with a distinctive spiral shape that is an exact mathematical equation.  A cross section of the shell displays the various chambers used by the animal.  The largest chamber at the front of the shell is where the animal lives, while the chambers behind are used for buoyancy so the nautilus can rise to the surface of the ocean or sink to the bottom.  The outer layer of the nautilus is a matte white with tan markings near the inner spiral.  When this layer is removed, the nautilus is a striking white with iridescent rainbows of color.  At the center of the nautilus, the shell is a pearlescent blue-gray color ovoid in shape.  When used in boxes and jewelry, it is called osmena pearl.
Chatoyancy:  The appearance of a line or a star within a gemstone when it is viewed in a certain light and at an angle.  Star sapphires and cat's eye chrysoberyl or tiger's eye stones exhibit this quality.  These stones are always cut as cabochons to bring out this quality.
Cloisonné:  A form of enameling in which colored glass powder is placed within tiny wire cells called cloisons.  When the piece is fired in a kiln, the glass melts and becomes a hard surface.  The terms, like most of the language of enameling, are taken from the French.
Coin Silver:  see SILVER.
Colored Gemstones:  A term used to describe all gemstones, in place of the vague and somewhat negative term, 'semi-precious'.  These stones are precious in their own right, and may even be more valuable than ordinary specimens of those known as precious.  Craft jewelers tend to use unusual colored stones, either clear, faceted stones such as amethyst, citrine, peridot, aquamarine, tourmaline or opaque stones such as turquoise, agate.  These stones may be FACETED or CABOCHON cut, depending on the quality of the gemstone material as well as the design they are intended for.
Cubic Zirconia:  The cubic form of zirconium oxide; grown in the lab.  One carat is about $100.
Culet:  The facet placed at the tip of a diamond.  It is known as the 58th facet. 
Cultured:  Usually referring to pearls, but also applied to certain colored gemstones.  Cultured pearls are grown within the oyster, but are given a start by the insertion of a bit of shell or mollusk tissue.  Cultured gemstones are grown in the laboratory using the same material as found in nature.

Demi-parure:  A matching set of jewelry, usually containing a necklace, earrings, and a pin.
Depletion Gilding:  A process by which the goldsmith burns out the base metals in a gold alloy to create a surface of pure gold.
Diamond:  The hardest material known, diamond is a highly compressed form of carbon.  The stone must be polished to bring out its beauty.  Diamonds, in spite of the popular slogan, are not always forever.  A diamond, which has grain like wood, can split along a cleavage line, either by accident or by the hand of the cleaver.  One carat is about $4,500.  Also see EMERALD CUT.
Dichroic Glass:  By mixing in certain additives such as titanium or aluminum, glass is created with two colors, visible under different viewing conditions.  One reflects light, the other transmits light.  The glass also picks up colors from the wearer's clothing, the effect is that the glass will change color before your eyes depending on how the light strikes it.

Emerald Cut:  Also known as rectangular cut, a geometric shape in which two sides of a stone are shorter than the other two.  The result, in diamonds, is an elegant, but quiet stone.  It demands a fine quality piece of ROUGH because there is little chance of hiding INCLUSIONS.
Enamel:  A term that covers several methods of melting glass powders to form a colored surface.  The most popular method in use today is CLOISONNÉ.
Engraving:  A method of decorating the surface of metal or a gemstone from the front by incising a design into the surface.  Small amounts of metal or gemstone material are removed in the process.

Fabrication:  Terms used by metalsmiths to indicate work made by hand.  It differentiates work made by CASTING.
Faceting:  The polishing away of diamond material to create a series of planes or facets on the surface of the stone.  The facets act as windows, allowing light to enter the diamond.  With precise faceting, the diamond reflects and refracts light.  Diamond polishing, or cutting, has gained in importance and is now considered a vital element in the value of the stone.
Fancy Color:  A term covering diamonds with strong body color.  Diamonds occur naturally in a wide range of colors from yellow to pink, blue and green.  The more intense the color, the more desirable.  While an off-white diamond is far less valuable than one with no body color, an intense canary yellow diamond is highly desired.  Pink diamonds were quite rare until the advent of diamond mining in Australia, where the Argyle mine produces a small but steady supply of intense purple-pink diamonds.  Two of the most famous diamonds in the world are fancies-the Tiffany Diamond is a canary while the Hope Diamond is a deep blue.
Fancy Cut:  A trade term for any diamond cut other than the brilliant, round or solitaire.
Faux:  A French word meaning 'fake' or 'false'.  It is often used to describe beads resembling pearls that have no actual pearl content but it is sometimes used in low-cost jewelry for glass stones emulating genuine COLORED GEMSTONES.
Filigree:  A Filigree design is lace-like ornamental detail made form intricately arranged wires.
Finding:  The small connectors that allow jewelry to be put on, such as clasps, hooks, and clutches for earrings.
Fine Silver:  see SILVER.
Fissure:  An elongated fracture or crack in the surface of a diamond or gemstone.
Flaw:  see INCLUSION.
Forging:  A hammering process to shape gold.
Freshwater Pearl:  Mollusks that are cultivated in lakes, mainly in China, and can produce cultured pearls like their SALTWATER PEARL cousins.  Enormous technical advances in culturing have led to pearls that are nearly round, at a much lower cost the the SALTWATER PEARL.

Gem Ammolite:  see AMMOLITE.
Geode:  A hollow rock (usually spherical) with crystals lining the inside walls.
Girdle:  The widest circumference of a gemstone.
Gold:  A yellow colored, soft, shiny metal commonly used in jewelry.  Pure gold, 100% gold, 24 karat gold that is at least 99.5% pure as it comes from the refinery.  See KARAT.
Gold Alloy:  For use in jewelry, pure gold is usually alloyed with other metals such as copper, nickel, silver, or zinc to add strength.  The metals used in the alloy also effect a change in the color.  Gold can be alloyed to be white, pink or red, green, or pale yellow depending on the metals used.  The purity of the resulting product is expressed in KARATS.
Gold Electroplate:  An electrolytic process in which fine gold is deposited onto a metal base.  The layer of gold in Gold plating is only required to be seven-millionths of an inch thick.  (The layer of gold in gold-filled products is about on hundred times thicker than gold-plating.)
Gold Filled:  A misnomer since the gold isn't filled with anything.  Rather, it is used as the outer layers of a sandwich.  The gold is permanently bonded by heat and pressure to a layer of karat gold.  In gold-filled products, the gold layer must be at least 1/20th (5%) of the overall product, by weight.  Any purity of gold may be used, most gold-filled products are made with either 12K or 14K gold.  The purity of gold used can be determined by the notation in front of the words Gold-filled.  14/20 Gold-filled and 14K Gold-filled both refer to a product in which 14K gold has been bonded to the base metal core.
Gold Overlay:  see GOLD FILLED.
Gold Plate:  Often confused with gold electroplate.  It is another term for GOLD FILLED.
Granulation:  An elaborate and ancient form of surface decoration, comprising tiny balls of pure gold individually applied to a HIGH KARAT GOLD surface.  The balls may be arranged in patterns or used in single rows to highlight a design.  The Etruscans perfected this technique around the 7th century BC.
Green Gold:  An alloy of gold and silver, copper and zinc that has a greenish cast; it is used to complement certain gemstones.

Hammering:  Small mallets are used to texture or shape gold by repeated blows.  See also:  ANTI-CLASTIC RAISING.
Hardness:  Hardness is a stone's ability to resist scratching, surface inclusions, abrasions or cracking.
High Karat Gold:  An expression for gold of at least 20 karat purity.  This term is common in contemporary goldsmithing in which goldsmiths want the want the rich color of high karat gold.  The higher the karat, the more yellow the gold.  Some designers alloy their own gold to achieve exactly the desired color, even matching the alloy to the gemstones being used.  Gold in small quantities can be alloyed with the heat from a hand held torch.

Inclusion:  A trade term for any foreign material found within a gemstone.  In diamonds, inclusions dramatically affect the ability of the diamond to reflect and refract light.  This has led to an elaborate rating system to describe the degree to which a diamond is 'included'.  Also known as flaws.  In emeralds, which are rarely without inclusions, elegant language such as 'silk' and 'jardin' (meaning garden) is used to turn a drawback into a virtue.

Karat:  A measure of the purity of gold based on a total of 24 parts.  Pure gold has 24 parts of gold and is called 24 karat or 24K.  Fourteen karat gold is 58% gold and is usually marked 14K; 18K or 18 karat gold is 75% gold and 25% other metals.  In the United States, an alloy must have at least ten parts of gold in order to be marked as gold.  Not to be confused with CARAT.

Lost Wax Casting:  see CASTING.

Malleability:  The ease with which a metal can be worked by stretching, rolling, or drawing it.  Gold is a very malleable metal and can be worked with hand tools.
Marquise Cut:  An elongated brilliant in which both ends taper to a point.
Matte Finish:  A muted surface finish achieved in a variety of ways such as sandblasting.
Melee:  A Melee is a small diamond, under 0.20 carats.
Moissanite:  Lab-created gemstone made of silicon and carbon.  It's made of silicon carbide, a mineral.  It has more brilliance, more fire, more luster than a diamond.  It is lighter than diamond.  It costs about a tenth as much as a diamond for the same carat size, one carat is about $450.  It won't scratch.  It is nearly as hard as a diamond.  Diamonds register 10 on a standard scale used by jewelers.  Moissanite registers 9.25, ahead of rubies and sapphires at 9 and emeralds at 7.5.
Mokumé Gane:  A Japanese term meaning 'wood grained'.  It is a sandwich of metals, often multi-colors of gold, that are then manipulated to form patterns.
Moroccan Ammonite:  Both ammonites and all of their close relatives are extinct, so very little is known about them except that they were sea creatures that thrived in the early Jurassic period (around 200 million years ago), and became extinct about the same time as the dinosaurs.
Mother of Pearl:  The iridescent substance that forms the lining of the shells of some fresh-water and some salt-water mollusks.  Like the pearl it is a secretion of the mantle, composed of alternate layers of calcium carbonate and conchiolin ( a protein substance that is the organic basis of mollusk shells).  Note the root word, conch, which many find familiarly in seashore locations.  Among the chief sources are the pearl oyster, found in warm and tropical seas, chiefly in Asia; the fresh-water pearl mussel, which lives in many rivers of the United States and Europe; and the abalone of California, Japan, and other Pacific regions.

Nautilus:  see CHAMBERED NAUTILUS.
Nickel Silver:  see SILVER.

Omega:  An Omega chain has closely interlocking links, which forms a flat, solid surface.
Opacity:  The quality of not allowing light to pass through.
Opaque:  Not allowing light to pass through; solid.
Osmena Pearl:  see CHAMBERED NAUTILUS.
Oval Cut:  An egg-shape cut in which both ends are gently rounded.

Parure:  A Parure is a matching set of jewelry, usually containing a necklace, earrings, brooch and a bracelet.
Patina:  A film, actually a form of discoloration, that occurs on the surface of metal after it has been exposed, either to the atmosphere or to chemical treatment.  In the hands of an artist, the patina becomes an integral part of the surface decoration.
Paua Shell:  Haliotis Iris - more commonly known as the Paua or Rainbow Abalone.  It can be found along the shores of New Zealand and the Philippines.  The outside of the shell is rough and dull, while the inside is a beautiful blend of colors.  The animal that lives inside this shell is black and it is the foot of the animal that is edible and marketed in many countries.  The shell is most commonly used in jewelry as well as inlays in such items  as furniture and guitars.  The word paua is actually Maori (a tribe in New Zealand) for abalone.  Abalone shells belong to the family Haliotidae and are nicknamed sea ears for their oval shape.  Because of the beauty of this shell and its relative thinness, paua shell tends to be more expensive. 
Pavé:  A setting technique in which small diamonds are placed closely together within a metal surface.  The appearance should be that of all stones making the surface looked paved.
Pearls:  see CULTURED, FRESHWATER PEARL AND SALTWATER PEARL.
Pear Shape:  A cut in which one end is rounded while the other ends in a point.  Proportions can vary greatly and a pear cut should be well balanced.  This is often the choice when a stone has inclusions at one end.  by trimming the end to a taper, the inclusions are eliminated and the value of the stone is increased.
Pink Gold:  An alloy of gold that includes copper.
Platinum:  A silver-white, dense and strong metal.  It is used in nearly its pure state in jewelry, and is alloyed with metals of the same group.  It is favored for use in PRONG SETTING because it is extremely strong.
Plumb Gold:  A trade term that means the item actually contains the amount of gold indicated such as 14K or 18K.  It dates from an earlier period in which manufacturers had a leeway of one-half karat and gold marked 14K could contain as little as 13.5 parts of gold.  Rarely used anymore.
Points:  A measure of weight for gemstones.  There are one hundred points in a CARAT.
Polished Paua Shells:  see PAUA SHELLS.
Precious Metals:  A term covering metals that are extremely resistant to corrosion by most means.  The precious metals group includes gold, silver and platinum.
Precious Gemstones:  A term commonly applied to the 'big three' of the colored gemstone world:  ruby, sapphire and emerald.  It is a misnomer however, since any one of these three can be of very poor quality and of little value whereas a colored gemstone of another type can have higher value.
Prong Setting:  A system of holding stones in place by means of small metal wires that allow the greatest part of the stone to be viewed.

Red Gold:  see PINK GOLD.
Repoussé:  A metalworking technique in which metal tools are used to create patterns on a sheet of metal.  The work is done from the back, unlike ENGRAVING or CHASING which are done on the front of the metal.
Reticulation:  Treating the surface of metal with heat or chemicals to make it melt and bubble to form interesting textures.
Rhinestone:  An artificial stone made of hard glass and cut to look like a gem.  One carat, starting at $3.
Roller Printing:  A technique in which sheets of metal are run through a small rolling mill along with another element such as fabric, mesh screen, leaves, anything that will be embossed into the metal.
Rope Chain:  A spiral-like chain with an appearance of two thick, woven strands.
Rose Gold:  see PINK GOLD.
Round Cut:  see BRILLIANT.
Rough:  A piece of gemstone material as it comes from the earth.  As the rough is cut or polished, gemstone weight is sacrificed for symmetry and beauty.  In the case of a diamond, at least half the weight of the rough is lost in the polishing.

Saltwater Pearl:  Pearls that are cultured in Japan, China and other areas are farmed in bays or inlets of the ocean.  Only under these conditions and in these kinds of mollusks can a hard object such as a clamshell bead be inserted to start the pearl culturing process.  With a round bead, the resulting pearl is likely to be round, or nearly so, which is not possible with a FRESHWATER PEARL.
Sandblasting:  A method surface treatment in which the metal is bombarded with tiny grains of sand that create texture.
Semi-Precious:  see COLORED GEMSTONES.
Silver:  A white colored, soft, shiny metal, commonly used in jewelry.  Like GOLD, silver is available in different levels of purity: the purest form, FINE silver, is 99.9% silver; STERLING silver is 92.5% silver, with other metals (usually copper) making up the remaining 7.5%; COIN silver is 90% silver with 10% copper.  NICKEL silver is an alloy of 65% copper, nickel and zinc - NO silver at all.
Simulated:  A substance meant to look like another, for example cubic zirconium, which is meant to look like DIAMOND.  It differs from CULTURED material in that it is a completely different material.
Solid Gold:  A term meant to imply KARAT GOLD, rather than GOLD PLATE or GOLD FILLED.  It does not mean an object is solid through and through.
Solitaire:  see BRILLIANT.
Sterling Silver:  Silver is measured on a scale of 1000 parts.  Sterling is 925 parts silver, 75 parts alloy.  Also see SILVER.
Surface Treatment:  Any of many methods used to enhance a metal surface such as SANDBLASTING.
Synthetic:  A term largely out of use that actually means a material that has been made in a laboratory but which is the same as the material it emulates.  It has come to be confused with imitation.

Texture:  The surface of metal that has been enhanced through SANDBLASTING, CHASING, ENGRAVING or other means.
Translucent:  Allowing some light to pass through, objects seen through translucent material are diffused or indistinct.
Transparent:  Easily seen through, allowing light to pass through without obscuring the ability to see objects on the other side.

Vermeil:  A frequently misused term.  It applies only to a base of sterling silver plated with karat gold.

White Gold:  An alloy of gold and 'white' metal such as silver, nickel, or zinc.

Yellow Gold:  Any alloy of gold in which the color remains true to the original color of the metal.  Yellow gold may be as high as 24K or as low as 10K, it may not be marked as gold in the United States.