Metals
Precious metals have been a part of human civilization for thousands of years. Although they were often believed to have mystical powers, precious metal was most attractive as a store of value (money) and for its beauty. Over time, precious metals came to symbolize wealth, power, and strength. Their scarcity, attractiveness and physical qualities make precious metals a prized part of any jewelry collection.

Gold
Gold has the longest and most storied history of all precious metals. It is soft enough to be worked into interesting shapes, and its warm color and scarcity gave it great value in early civilizations. It has been the foundation of many monetary systems, and remains important to our economy even today.

As jewelry, it was gold's softness and natural beauty that made it appealing, in addition to the fact that it doesn't corrode or tarnish. It is so soft, in fact, that pure gold is rarely used in jewelry. It is mixed with another metal, usually copper or silver, to make a stronger gold alloy, or mixture of metals. The quantity of gold in a given alloy is expressed in karats (abbreviated as K or KT). Pure gold is 24K; 18K gold is 75% gold and 25% other metals. In other words, each karat is equal to roughly 4.17% of the total of the alloy.

As the karat weight drops, the metal becomes more durable but less yellow. Sometimes gold that is a lower karat weight will be plated in high-karat gold to enhance the color. This is perfectly acceptable as long as you pay a fair price. Also keep in mind that gold plating will wear off with time and your jewelry may need to be re-plated.

When buying gold jewelry, look for a stamp with a karat mark, the manufacturer's registered trademark and the country of origin.

White Gold
White gold has the same properties as yellow gold, but it has been mixed with different metals to give it a white color. Instead of the copper and silver used in yellow gold, white gold contains such metals as nickel, zinc, or even platinum. However, white gold should not be confused with platinum, which is much rarer than gold and hence more valuable.

The karat weight system used in white gold is the same as that used in yellow gold (see the "Gold" section on this page). 18K yellow gold and 18K white gold contain the same proportion of gold; only the remaining 25% of the alloy is different. Sometimes, white gold is plated with an even whiter metal, such as rhodium (a very rare member of the platinum family), to enhance its appearance.

White gold was developed to give a different look to jewelry. The white color is an excellent setting for very white diamonds, and when used side by side with yellow gold, it creates a striking effect. Jewelry using both white and yellow gold is called "two-tone."

Platinum
The most precious metal commonly found in jewelry is the silvery-white metal platinum. It is a relative newcomer to jewelry, having become popular in the past 200 years or so. Like gold, it is rare and heavy, but it is more durable than gold and is sold in purer form. It is sometimes mixed with a little bit of iridium and ruthenium, which are similar to platinum but much rarer, for added strength. Platinum is not sold according to karat weights. It is stamped PT or plat in the United States to indicate that it is platinum.

Because of its purity, platinum is excellent for people who are allergic to other metals. Its light color also makes it popular. Like white gold, it makes very white diamonds appear bright.

Platinum has enjoyed an enormous resurgence in popularity in recent years. It has a very understated and old-fashioned look that has come back into style, leading more jewelry designers to work with this metal.

Silver
Silver has a history almost as ancient as gold. It is bright and durable and much more plentiful than gold. However, it does tend to tarnish, making it less popular in some forms of jewelry.