
Different alloy combinations have their own unique working properties and characteristics, and are best suited to specific manufacturing methods
Common platinum alloy ingredients contain other platinum group metals such as ruthenium, iridium and palladium
At 100% purity, platinum is too soft for jewellery use. For jewellery, platinum is typically used as an alloy containing 95% platinum and 5% other metals.

For products that consist of at least 950 parts per thousand (ppt), these products can be described and marked as platinum or an abbreviation of the word (PLAT)
According to US Federal Trade Commission guidelines, all platinum jewellery should be marked to indicate the purity of the product


90% Platinum alloyed with 10% Iridium is hallmarked as 900 Pt Ir
900 Pt Ir is a universal alloy that is used for many manufacturing applications
900 Pt Ir has machining limitations due to the lower hardness of 100HV


95% Platinum alloyed with 5% Cobalt is hallmarked as 950 Pt Co
950 Pt Co is an excellent alloy for casting
950 Pt Co is ferromagnetic, so it is attracted to magnets
950 Pt Co oxidises at 1000 °C
950 Pt Co has a hardness of 135HV


95% Platinum alloyed with 5% Ruthenium is hallmarked as 950 Pt Ru
950 Pt Ru is an excellent all-purpose alloy that is ideal for fabricating, machining and casting
950 Pt Ru has a hardness of 135HV