When used as prongs and other setting components, platinum holds fine gemstones firmly in place for the life of the jewelry.The metal's natural white luster provides a rich backdrop for diamonds.

In addition, it's a metal that's just as elegant when used all by itself to create a piece of jewelry, either a simple polished item or a design with engraved motifs. Platinum also looks stunning when mixed with contrasting touches of 18K yellow gold.

The Platinum Group of Metals and Platinum Marks

There are six related metals belong to the Platinum Group of Metals: Platinum, Iridium, Palladium, Ruthenium, Rhodium and Osmium.

Jewelry can contain different percentages of pure platinum. The US Federal Trade Commission, FTC, publishes guidelines for acceptable marking standards for platinum jewelry sold in the U.S.

Platinum content is usually expressed as the amount of pure platinum the jewelry contains in parts per thousand. For example, mix up a huge bucket of fruit juices that contains 1,000 ounces--900 hundred of the ounces are plain apples and 100 are pears. That makes the apples 900 parts per thousand of your mix.

Another way to express this is as follows: the apples make up ninety percent of the mix--900 divided by 1000. Jewelry that contains at least 950 parts per thousand of pure platinum may be marked or described as "Platinum".

Jewelry that contains 850, 900 or 950 parts per thousand of pure platinum may be marked "Plat" or "Pt" if a number is used in front of the term to disclose the amount of pure platinum in the mix, such as: "850 Plat" or "850 Pt", or "950 Plat" or "950 Pt".

Jewelry that contains at least 950 parts per thousand of platinum group metals, with at least 500 parts per thousand of the total pure platinum, may be marked as platinum as long as the numbers of each metal are disclosed.

For example, "600 Pt. 350 Ir." or 600 Plat. 350 Irid." indicates an alloy that is 600 parts pure platinum and 350 parts iridium. "550Pt. 350Pd. 50Ir." or "550Plat. 350Pall. 50Irid." indicates an alloy that is 550 parts pure platinum, 350 parts palladium and 50 parts iridum. Ask your jeweler to explain platinum content and markings if you are not sure which combination is the most suitable for your jewelry purchase.