Platinum is one of the softest metals. But when it is alloyed with other metals, normally 10% iridium, it becomes one of the hardest metals. This hardness makes platinum ideal for jewelry with diamonds and other valuable stones because it provides the most secure material for setting gems.
Left to right: Silver, platinum, 18k white gold
Platinum is white in color and is often mistaken for white gold. However, platinum carries higher costs than gold because it is denser and is more difficult to fabricate, due to its higher melting point.
(U.S. law governing trademarks and quality marks for gold and silver do not yet apply to platinum, but this is being changed. Europe and Canada already include platinum in their marking laws.)
The following chart (from kitco.com) illustrates the volatility of platinum prices from March 1992 to March 2003.
For current prices of platinum, visit this page on kitco.com. And, for more information, explore the Kitco Web site for data on the prices of precious metals. You can build your own charts using time-frames you select.
While the cost of materials greatly affects the price of jewelry, workmanship is also a factor.
The bottom line is that you should buy a piece of jewelry because you love it, not as an investment!