Platinum is increasing in popularity immensely despite its high price compared to more traditional gold and silver jewellery. The main reason for the high cost of platinum jewellery is that the metal is quite rare. Platinum miners have to mine around 10 tonnes of raw platinum ore to produce just 1 ounce of pure platinum. The fact that unlike gold and silver there are no large stocks of platinum in reserve above ground also serves to keep prices high. Therefore there are no backup reserves of platinum to meet the demand for the precious metal if minimg activity under produces.

Platinum is not an easy material for jewellers to work with due to its high melting point of 1800 celsius. But it does lend itself to producing some amazing designs of very fine jewellery. The properties of platinum allow just a single gram of the precious metal to be stretched to over a mile in length meaning very delicate mesh or similar jewellery designs can be created with platinum. The assay office recognise platinum in various different purities from 85% to 99.9% platinum. UK hallmarks are applied in 850, 900, 950 and 999 parts per thousand for platinum items. The metal is usually alloyed with palladium or cobalt for best results in the production of jewellery.

Platinum jewellery is commonly produced using a method called investment casting. A wax form of the jewellery item is used to make a cast out of a liquid ceramic known as investment powder. When the investment powder mixture has hardened around the wax model of the jewellery piece the wax is melted away leaving a mould for the platinum. The mould is then filled with the molten platinum alloy to form the jewellery piece that is then removed from the mould to be finished and polished.

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This entry was posted on Wednesday, August 30th, 2006 at 1:24 pm and is filed under Platinum. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.