Pt800 Platinum
Pt800 Platinum
An 80-per-cent platinum alloy at the lower bound of jewellery use
Pt800 is a platinum alloy containing 800 parts per thousand of pure platinum (80%), with the remaining 20 per cent composed of alloying metals such as iridium, palladium, ruthenium, or cobalt. The alloy sits at the lower end of the platinum jewellery range and is rare in fine work, where Pt950 and Pt900 dominate. Pt800 retains the white colour and broad noble-metal character of higher-purity platinum but at reduced cost and with somewhat reduced corrosion resistance and prestige.
Properties and standards
The higher proportion of alloying metals in Pt800 increases hardness and reduces material cost relative to Pt950 or Pt900. The alloy is harder to polish to the same depth of platinum-white lustre that buyers expect from higher-purity stock, and the colour is fractionally less white. Importantly, Pt800 is not universally accepted as platinum under all international hallmarking regimes: the United Kingdom Hallmarking Act and several other jurisdictions require a minimum platinum content of 850 parts per thousand for the platinum hallmark to be applied. In markets where Pt800 cannot legally be marked as platinum, it is sold under generic descriptions and at correspondingly reduced prices.
In the workshop and the trade
Pt800 is uncommon in fine jewellery, where the modest material cost saving relative to Pt900 or Pt950 does not generally justify the loss of prestige and the regulatory complications. The alloy appears most often in mass-market production for markets that accept the lower fineness, and in industrial or specialty applications. Buyers should be aware of the standards in their local market and ask explicitly whether a piece described as platinum meets the local hallmarking minimum. The trade convention in the principal Western fine-jewellery markets is to specify Pt950 by default and to disclose the actual fineness on retailer documentation.