Platinum
From RPGWW Wiki
Platinum is a metal that's considered even prettier than gold. As such, it's valued higher than the yellow metal, and is used in quite a bit of jewlery and decoration. Platinum is much like gold in toughness and mallebillity, so you won't find many platinum swords being used. However, it is used quite frequently in an alloy with silver to add decorations to weapons made of more mundane materials.