Posted on 12th Apr 2012 @ 10:33 AM
Gold is classed as a noble metal because of its permanence and durability. It doesn’t weather when it comes in contact with the air or with acids, and it can be melted and re-melted without any loss of weight. But gold is too soft to be used on its own to make jewelry, and so various alloys are added to the precious metal to harden it. These include silver (which is also sometimes considered to be a “noble” metal), copper, zinc, cadmium and nickel. The secret though is how these elements are balanced to maintain the color of the gold.
This is where hallmarks come in. Better known as the karat (or carat) system of classification hallmarking, has been used since about the 4th century AD (particularly in Europe). In the United Kingdom hallmarking of precious metal jewelry has been required, by law since 1300.
In the USA most gold jewelry is stamped to show its karat quality, but according to the Federal Trade Commission,this is not a legal requirement.
Where the karat quality mark is used to identify the quality of gold jewelry, the metal is “assayed” or analyzed by an independent organization to ascertain how much pure gold is in the metal. It is then stamped to show how many karats it contains. This stamp can be found on the inside of gold rings or bracelets, and on the clasp of most gold chains.
As a guide, 24 karat indicates that the item is pure gold, while 18 karat indicates that there are 18 parts of gold and 6 parts of an alloy. If your ring is marked 9 karat gold, it contains only 37.5% gold and the rest is an alloy.
Various marking techniques and stamps are used in various parts of the world; and in addition to the karat identification, there is usually also a stamp that shows where in the world the jewelry was assayed. In the UK there are different marks for different cities. Sometimes the maker’s mark is also stamped onto the jewelry, which can add value to the piece, especially long term.
Sarraf.com offers a great selection of both 18 and 14 karat items including chains, bracelets, rings and other jewelry treasures.