Platinum

Platinum Alloys

Platinum alloys are stronger and denser than most gold alloys. Platinum has a high melting point, even higher than gold. Pure platinum can be readily welded and soldered and takes a lustrous polish, but it is usually too soft for engagement jewelry.

Small amounts of certain alloying elements can give platinum the properties that make it ideal for jewelry. Copper, cobalt, gold, iridium, palladium and ruthenium alloy easily with platinum.

Platinum

Platinum is a whitish-gray metal that is thirty times as rare as gold. In fact, if all the platinum in the world was poured into an olympic sized pool, it would barely cover one's ankles - all the world's gold would fill more than three pools. Moreover, platinum is twice as dense as gold; a platinum ring will be twice the weight of an identical ring cast in gold. And what makes platinum even more expensive, is the fact that one ounce of refined platinum takes up to ten tons of mined platinum ore, whereas an ounce of gold requires a mere 5 tons.

The general rule is that an alloy of platinum (see discussion on alloying) tends to be harder than an equivalent alloy of gold. A 95% gold alloy (95% gold content and 5% alloy) would typically be softer than a 95% platinum alloy. Platinum will resist breaks, chips & cracks, and heat & chemicals better than gold. And, because of its higher density and strength, platinum tends to retain its finish and wear better than gold.

Nearly all Platinum is 950 (95% pure) with just 5% alloy. Once well polished, platinum will maintain its finish virtually tarnish free forever. As with any metal, the polished surface of some platinum alloys may scratch with every-day wear. But when it does scratch, the metal is not lost, merely displaced. Thus, the volume of Platinum in a setting should last a lifetime. Over time, matte finish platinum tends to burnish and highly polished platinum tends to matte.

With reasonable protection from knocks and abrasion, highly polished platinum can be brilliant and kept that way. A large proportion of platinum-palladium alloy is plated thinly with rhodium, which scarcely alters the color but does impart some extra wear resistance (see discussion on rhodium electroplating). To add to its already impressive array of features, platinum is also hypoallergenic - providing a lifetime of allergy-free durability to its fortunate owner.