Jewelry
Platinum Group of Metals Used in Jewelry
Platinum Group metals (Pt, Ir, Pd, Ru, Rh, Os)
Group of precious metals (platinum, iridium, palladium, ruthenium, rhodium, and osmium) that share similar chemical and metallurgical properties.
- Much platinum used in jewelry is composed of 90% platinum and 10% iridium, which makes it much harder than pure platinum.
- 5% ruthenium serves the same purpose.
- Similar to gold, platinum purity and alloys are commonly stamped.
- Unlike gold, purity is stated relative to 1000 parts, e.g. "950Plat" is 95% pure platinum.
- Palladium and small amount of rutheniumare used in setting heads for platinum jewelry; lighter, less expensive.
- Rhodium is used as a plating metal. It gives white gold and platinum a hard, bright finish and slows tarnish on stainless steel.
- Platinum has a specific gravity of 21.45.
Platinum is about 11% heavier than 24K gold and 60% heavier than 14K gold.
Platinum is "whiter" than white gold. Platinum, it is claimed, has a luminescence that white gold hasn't.
