Platinum

Platinum is a pure, silvery-white metal prized for its rarity and beauty. The name "platina" came from Spanish explorers in 1735 and, ironically, means "silver with little value." Today, we know that ounce for ounce, platinum is the most expensive precious metal because of its rarity, purity, and durability. Unlike gold, platinum usually is not alloyed with other metals.

Gold and Silver

Gold and silver — 2 regal elements known as precious metals — have been prized for thousands of years for their beauty and rarity as well as their hardness and resistance to corrosion. Because of these qualities, precious metals are universal symbols of strength, wealth and power. They are a prized and indispensable part of any jewelry collection. Here are some basic facts and tips that will help you when you're shopping for fine jewelry of gold, silver, or platinum.

Gold

Gold is the oldest precious metal known to humankind. The metal's luster and remarkable properties have allowed it to be crafted into the world's most coveted and exquisite jewelry.

Gold is the world's most malleable (able to be pounded thin) and ductile (able to be drawn to a fine wire) of all metals. In its pure state, gold is too soft to be worn for jewelry, so it is usually mixed with other metals, such as silver, copper, nickel and zinc, to make it harder. A mixture of metals is called an alloy. The quantity of gold in an alloy is expressed in Karats (abbreviated as k or kt). The following chart shows the proportion of pure gold in the most common karat counts:

Gold Purity by Karat Count

Here are the most common colors of gold alloys and the metals used in making them:

Colors of Gold Alloys

Gold jewelry is stamped with its karat content (usually 10 karat, 14 karat, 18 Karat, or 24 karat), so you can be certain of the quality and value.

Gold-Filled Jewelry

Gold-filled jewelry contains a layer of gold on a base metal. The percentage of gold must be at least 1/20 of the total weight of the piece.

Gold-Overlay Jewelry

Gold-overlay is a layering process in which a base metal is layered with gold. Gold-overlay jewelry is created with the following guidelines:

  • Gold-overlay jewelry uses either 14kt or 10kt gold

Vermeil Jewelry

A Sterling silver base that is coated or plated with gold or gold alloy, Vermeil jewelry is created with the following guidelines:

  • The gold coating must never be less than 10kt in fineness.
  • The minimum thickness for this coating must be 3 microns. (A micron is a measurement of thickness used in the jewelry industry.)

Silver

Silver has a long and noble history, second only to that of gold. Popular as a jewelry metal for thousands of years, it is harder than gold and much more plentiful. The abundant supply and ease of working it make silver more affordable and a good alternative to gold and platinum. Silver does require polishing because it will tarnish.

Sterling silver is a silver alloy with a fixed standard of purity. It consists of 925 parts silver (out of 1,000) and 75 parts copper. Like gold alloys, sterling silver can be used to plate other metals.