Abstract: Platinum is one of the Noble Metals, the other two being that of gold and silver. Platinum is an extremely rare metal and it occurs at a concentration of less than .005 parts per million on the Earth’s crust.
Platinum is often the choice of jewellers to create fine jewellery, especially when the centre stone to be set is of a high value diamond or other precious colored stone. Its heavy weight and durability make the metal very suitable as it does not wear off easily. For jewellery setting it can hold the center stone and small ascending diamonds firmly in place in its prongs.
Platinum has a natural white, slightly greyish lustre which can make diamonds appear whiter that they really are. However, over time platinum will not fade to yellow unlike white 18K gold but its shiny finish will get dull to a natural patina. Hence, if you have a platinum engagement ring, you should send it to the jeweller once every year for re-polishing and recoating with rhodium.
In the group of Platinum, there are 5 rare metallic elements that occur in association. These are platinum, iridium, palladium, ruthenium, rhodium and osmium. Of these, platinum itself is the most abundant. Jewelleries made from platinum typically is an alloy of platinum and an iridium. Rhodium is used primarily for coating to give it a shiny bright finish.
In the jewellery world the hallmark of a jewellery item when it is of platinum construct, should be the following convention:
- When a jewellery item contains at least 950 parts per thousand, it may be marked as “Platinum”
- When a jewellery item that contains 900 or 950 parts per thousand it may be marked as 900 Pt or 950Pt.
For the last two years, platinum seems to lose some of its lustre as the international price for platinum is about half of that of gold. Anyway, to connoisseurs of jewelleries or to high bench jewellers, platinum is still the metal of choice for setting engagement ring.
Photo Credit: Weddingbands.com, mcalvanyica.com, sdbullion.com, Wikipedia.com