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 "whiter" than white gold.
Platinum, it is claimed, has a luminescence that white gold hasn't.
