Guide to Precious Metals

SILVER:

Silver, a malleable and plentiful metal, costs less than other precious metals, but tarnishes easily and requires frequent care and cleaning. Too soft for use in jewelry in its pure form, most silver jewelry is sterling silver (92.5-percent silver and 7.5-percent copper). Sterling silver should be marked "sterling," "925," or "ster." Sterling Silver is used in a wide variety of fashion jewelry at affordable prices, but is not meant to endure the weathers of time. When purchasing a keepsake, it is recommended to consider more durable metals.

 

GOLD:

Gold, a soft and highly-malleable metal, does not tarnish easily and comes in a variety of colors. Gold costs more than silver and its softness can result in scratching and denting in its pure form. Gold's purity is measured in karats. Pure 24K gold is too soft to securely hold a stone so gold is alloyed with other metals such as silver, copper, and zinc to make it sturdier. Gold jewelry should be stamped with the karat mark ("K") along with the manufacturer's trademark and country of origin (if outside the U.S.). European karat markings are different than those in the U.S.

 

U.S.

European

Percent Gold

24K gold

1000

100 percent

18K gold

750

75 percent

14K gold

585

58.3 percent

10K gold

417

41.6 percent

 

PLATINUM:

The purest, rarest, and most prestigious of all the precious metals, platinum is hypoallergenic, strong, durable, and tarnish resistant. Platinum is the most dense metal of the three, and thus is paramount in durability. Five heavy metals with similar chemistry and weight (iridium, osmium, palladium, rhodium, and ruthenium) naturally alloy platinum. Unlike gold, platinum jewelry contains platinum in nearly pure form. It should bear a stamp with a symbol to reveal purity.

 

PLATINUM AT A GLANCE

Pure

Platinum jewelry is generally 95% pure, unlike 18 karat gold, which is 75% pure. No metal is completely pure and all have alloys - blends of other metals. Platinum has few alloys, making it so pure it doesn't fade or change color and it retains its shine for years. The pure white luster of the metal reflects the true brilliance of diamonds; provides the best setting for precious jewels. Platinum's purity also makes it kind to the skin because, unlike some alloys in other metals, it does not cause allergic reactions.

Rare

Platinum is 30 times rarer than gold and is found in very few places in the world, mainly South Africa and Russia, and to a lesser extent in Zimbabwe, Canada and South America. Every year only 88 tons of platinum are made into jewelry, compared with 2,700 tons of gold. It takes eight weeks to produce one single ounce (31.1 grams) of platinum. There are also fewer platinum mines. For every 10 gold mines there is just one platinum mine.

Eternal

Platinum's density and weight make it more durable than other jewelry metals. A six-inch (15 cm) cube of platinum weighs 165 lbs (75 kg), the same as an average man. Platinum is also resistant to heat and acids and has a high melting point - 3,223ºF (1,768ºC). Platinum doesn't wear away and holds precious stones firmly and securely. Some of the world's most famous gems are set in platinum, such as the Koh-I-Nor diamond, part of the British crown jewels. All precious metals can scratch, and platinum is no exception. However, the scratch on a platinum piece is merely a displacement of the metal and little of its volume is lost, whereas scratching gold wears it away and decreases its volume. If visible scratches do appear on a platinum piece, a qualified jeweler can re-polish it.

Versatile

In addition to its strength and density, platinum has another remarkable quality - pliability. Platinum is so pliable, that just one gram of the metal can be drawn to produce a fine wire over one mile (almost 2 km) long. This quality has enabled jewelers to create some amazing versatile platinum mesh accessories, which could not be fashioned from other precious metals. Platinum is also in demand in other fields - it is used in industry, most notably in catalytic converters. Platinum also plays an important role in medicine. It is not affected by the oxidization reaction of blood, has excellent conductivity, and is compatible with living tissue. Because of these properties, platinum is used for pacemakers. At present, more than 50,000 people are living healthily on pacemakers. Platinum is a life-saving metal for these people.