Some interesting terms of the jewelry manufacturing industry

Alloy: A combination of two or more metals usually formulated to provide or increase desired properties.

Alpaca Silver: The same as nickel silver. No silver content. The term used most to describe some jewelry from Mexico and South America.
Base Metals: Non-precious metals such as copper, zinc, nickel, etc.
Casting: The method of duplicating an object by pouring metal into a hollow mold formed by the original object. Almost any jewelry object that can be made by hand can be reproduced by the lost wax or centrifugal casting process.
Coin Silver: An alloy of 90% fine silver and 10% copper.
Electroplating: In the jewelry industry, the use of electricity to deposit a thin layer of precious metal on the base metal of a jewelry item.
Fine Silver: Silver that is 999 fine or higher. (On a scale of 1000)
German Silver: Another name for nickel silver. A composition of nickel, copper and zinc, it contains no silver.
Gilding: The coating of a surface with a thin layer of gold. Electroplating is the modern form of gilding.
Gold Filled: Bonding a layer (or layers) of gold alloy to a base metal and then rolling or drawing the metal to the thickness desired. The gold content must be 1/20th or more of the total weight of the metal in the piece.
Handmade: A term that can be applied only to jewelry objects made entirely by hand, without the use of machine tools.
Handwrought: This term implies that the jewelry article was made partly by machine and partly by hand.
Karat: A measure of fineness; 24 karat is fine gold. One karat equals 1/24 (.0417%), so that 14 karats is 14/24 fine gold and the balance 10/24 is alloy. If the gold content of an alloy is less than 10/24 the object cannot be represented as karat gold.
Nickel Silver: A composition of nickel, copper and zinc. It contains no silver. Also known as German Silver.
Silverfilled or Silver Overlay: A layer of sterling silver bonded by heat and pressure to a layer of composition metal (#752 nickel). The ratio of precious to composition metal, by weight, is expressed with a percentage.
Pennyweight: The twentieth part of a troy ounce. The name originally applied to the weight of an Anglo-Norman penny.
Precious Metals: Gold, silver, and the platinum group metals are known as the precious metals. Some craftsmen also call them the noble metals.
Roman Gold: A finish on gold jewelry produced by matting or frosting the surface, then electroplating it with pure gold. This provides a soft matte finish with a rich yellow color.
Sheffield Plate: Originally made by bonding sheet silver to copper, rolling and manufacturing the bonded metals into hollowware. Imitations are made by electroplating silver on copper and are sometimes erroneously advertised as Sheffield plate.
Silver Plated Ware: Made by electroplating fine silver on a base metal alloy – usually nickel silver or Britannia metal, sometimes brass or copper.
Solid Gold: Fine gold or gold of 24 karat. The term “solid gold” should not be applied to articles of lesser quality.
Sterling Silver: Must be 925/1000 (92.5%) fine silver and 75/1000 (7.5%) copper. This proportion is fixed by law.
Sterling Silver Overlay: Top layer, 20% of the thickness of the metal, is Sterling Silver. This is used for engraving. 80% is nickel silver which gives strength to the piece. Commonly used in belt buckles, money clips, and horse tac.
Troy Ounce: From the troy system of weight used for measuring precious metals, based on a pound of 12 ounces and an ounce of 20 pennyweights or 480 grains. Precious metals are measured in troy ounces worldwide.
White Metal Alloy: For jewelers, white metal (babbit) alloy is tin and antimony.