Whiteflash-Diamond Playground

100% platinum is called ‘fine platinum’ in the jewelry trade. When cast it has a Vickers hardness of 52, which is too low for common jewelry applications. It will easily dimple, resist polish and is extremely scratchable (like lead). The 5% metal by weight that’s alloyed with platinum to create Pt950 is what makes it hard enough to be usable in jewelry while keeping the density and malleability for which platinum is treasured. There is a 999 Platinum alloy (99.9% platinum) advertised as much harder than 100% cast platinum. This is because it is not cast: Some specialty alloys, Pt-Gold and Pt-Tungsten among them, can be heat treated or aged to have twice the normal hardness but in reality they behave more like steel than precious metal alloys.  We can expect new alloys regularly; there are hundreds on the market and twists are being developed all the time. This is similar to specialty diamond cuts with extra facets – marketers love to try new things. Like specialty cuts, many specialty alloys will come and go. Those which are worthy and stand the test of time will stay.