Precious Metal Guide

Fine Silver vs. Sterling Silver

Fine silver is 99.9% pure. Sterling silver is an alloy of silver containing 92.5% by weight of silver and 7.5% by weight of other metals. The sterling silver standard has a minimum millesimal fineness of 925.

14K, 18K, Yellow & White Gold

While pure gold is yellow in color, colored gold can be developed into various colors. These colors are generally obtained by alloying gold with other elements in various proportions. White gold is an alloy of gold and at least one white metal. Like yellow gold, the purity of white gold is given in karats.

For example since 24K is pure, alloys which are mixed 14 parts gold to 10 parts alloy create 14-karat gold, 18 parts gold to 6 parts alloy creates 18 karat, and so on. This is often expressed as the result of the ratio, i.e.: 14/24 equals 0.585 and 18/24 is 0.750. There are hundreds of possible alloys and mixtures, but in general the addition of silver will color gold white, and the addition of copper will color it red. A mix of around 50/50 copper and silver gives the range of yellow gold alloys the public is accustomed to seeing in the marketplace. A small amount (0.2%) of zinc can be added to harden the alloy.

The most common grades of gold, in addition to pure 24K, are 22K (92%), 18K (75%), 14K (58%).