Platinum
A dense, naturally white precious metal used in fine jewelry, usually as 95% or 90% pure alloys.
Purity
Platinum jewelry is usually 95% pure, marked Pt950 or 950, or 90% pure, marked Pt900 or 900, depending on the market. The remaining metals, such as ruthenium, iridium or cobalt, adjust hardness and workability.
Properties
- Naturally white, so it does not need plating to stay white.
- Dense, a platinum ring weighs roughly 30 to 40 percent more than the same ring in 18k gold, and around half as much again as 14k gold, depending on the alloys.
- Durable, when platinum is scratched the metal is mostly displaced rather than lost, and it develops a soft patina over time.
- Hypoallergenic for most people.
Platinum versus white gold
Freshly plated white gold and new platinum look very similar. Platinum looks a little greyer and deeper, plated white gold a little brighter and cooler. Over time white gold can turn warmer as the rhodium wears, while platinum stays white with a satin patina.
Rendering platinum
Use a white metal material with a slightly greyer, deeper tone than rhodium plated white gold, and keep roughness low for a polished finish. If you sell the same design in platinum and white gold, render both with the same environment and camera so the subtle difference is shown fairly.
Estimating weight
Because platinum is so dense, weight and cost change a lot between platinum and gold. Use the metal weight calculator with your CAD volume to compare.