Gold, Silver, Platinum, and Palladium are known as the Precious Metals in the jewelry industry. They are also known as the Noble Metals.
Copper, Zinc, and Brass are known as basic metals in the jewelry industry.
It is a unit to measure fineness-24 karat is fine gold. One Karat equals 1/24 (0.0417). Thus 14 Karat is 14/24 fine gold and the balance (10/24) alloy. If the gold content of an object is less than 10/24 the object cannot be signified as karat gold.
Colors of Gold
One can have yellow, green, red and white gold produced by variations in the alloy. Silver and zinc tend to give a green color, copper-red, and nickel-white.
"Solid Gold" means fine gold or gold of 24 karat.
Gold filled is made by electrolyticallly depositing fine gold on a base metal. The plate thickness must be at least 0.000007, then it can be marked as gold washed or colored.
Fine silver means pure silver i.e. it contains no alloy material.
Sterling silver (92.5%) fine silver and rest copper. It is called coin silver because it was used for U.S. silver coins before 1966.
Commercial silver is a term applied to silver that is 99% (or more) fine silver.
Foreign silverware contains varying percentages of silver. It may be as low as 10%.
Silverware made in Denmark, which is 83% fine silver.
Silver Plated Ware
Silver plated ware is made by electroplating fine silver on a base metal alloy usually nickel silver, Britannia metal, brass or copper.
Nickel silver is a composition of nickel, copper and zinc. Surprisingly it contains no silver.
Britannia metal is a composition of tin, copper and antimony.
Pewter was primarily a tin-lead alloy. It is now made in a tin, copper. Antimony composition is similar to Britannia metal.
High brasses run from 55% copper in the extruded brass to 70% copper in the deep drawing brass, the balance being zinc.
Low Brasses contain 80% or more copper, the remaining is zinc.
It originally means weight of a grain of wheat of this unit is hardly in use now.
A pennyweight is the 1/20 of a troy ounce. The name originally applied to the weight of an Anglo-Norman pound.
An Ounce (troy) is about 10% heavier than the common avoirdupois ounce. There are 14.583 ounces troy in an avoirdupois pound.
This term is applied to jewelry objects made entirely by hand without the use of machine tools.
Hand wrought means that the jewelry article was made partly by machine and partly by hand.
Carat is a unit of weight & equals to 3.086 grains or 1/5 of a gram.
The word "perfect" portray any diamond without flaws, cracks, carbon spots, clouds or other blemishes or flaws when examined under a 10-power magnifier.
A diamond is called blue white if it has traces of only blue colour & no other colour.