For many years gold has been used for designing jewelry. In its natural form it is a dull yellow-orange metal. But in the hands of expert jewelers it becomes exquisite gold jewelry. The pure form of gold is very soft and is easy to work with. It does not react with skin and can be easily drawn into thin wires or beaten into sheets which are then turned into beautiful jewelry. However, the pure form of gold is rarely used to make jewelry. This is because gold is too soft, and can easily break or change shape under pressure. It is therefore mixed with other metals like nickel, copper or zinc to give it tensile strength, and then turned into jewelry.
It is for the jeweler to decide how much metal he wants to mix with gold. But he is required to indicate this to all customers. The metric that is used to indicate the purity of gold is called karats. Under this, 24 karat gold is pure gold. Eighteen karat gold means that the alloy has 75% gold, while in 14 karat gold, the gold percentage drops to 58.5. Similarly, 10 karat gold contains only 41.7% gold, the rest is another metal. The gold gets a brighter luster and sheen according to the metal that is added to pure gold. Sometimes a red or greenish tinge can also be given to gold jewelry.
Besides gold jewelry, gold plated and gold filled jewelry are also very popular. They are not pure gold articles and hence can be purchased at low costs. In the case of gold plated jewelry a thin layer of gold is added to a base metal by electroplating. If worn consistently the gold polish can wear off within six months. A thicker layer of gold is added in gold filled jewelry than in gold plated items. It is more expensive than gold plated jewelry and its shine lasts longer.
Jewelers have also used plated gold over sterling silver which acts as the base metal. This is called as vermeil and is more costly.