The alloy mixture in this ring is specific to a design and manufacturing company in North America. It’s made of 950 platinum combined with ruthenium and palladium. In this case, it is necessary to get sizing stock directly from the company that uses this particular alloy, which is different from commercially available sizing stock.
It is vital to match the platinum alloy of the insert with the alloy mixture of the ring. Color, compatibility, and visibility of solder junctions are the common problems when alloys don’t match.
Jewelry manufacturers generally make platinum jewelry with commonly available platinum alloys. An internationally accepted standard for jewelry is a mixture purity of 95%, or 950 parts platinum and 50 parts other metal/metals.
The most common alloys are 950 platinum/50 ruthenium and 950 platinum/50 cobalt. There’s also a wide range of other mixtures.