Platinum Metals Rev., 1975, 19, (2), 63
Platinum Is Given a Hallmark
From the beginning of this year all platinum jewellery in the United Kingdom is subject to hallmarking under the provisions of the Hallmarking Act of 1973. Platinum alloys for jewellery have thus been brought into line with carat golds and sterling silver in that legislation now defines the minimum acceptable purity.
The platinum hallmark—an orb within a pentagonal shield—will be applied by the Assay Offices in London and Birmingham, together of course with the appropriate maker’s mark, Assay Office mark and date letter, after analysis has established that the alloy contains a minimum of 95 per cent of platinum.
The method that has been adopted after a lengthy investigation of possible means of analysis, is atomic absorption, on the grounds of its suitability for use on small articles and its rapidity, both essential factors in the handling of large numbers of samples where results are required very quickly.
The first pieces of platinum checked by the London Assay Office were ceremonially hallmarked in the presence of the Prime Warden of the Worshipful Company of Goldsmiths, Sir Harold Himsworth. The first piece to be hallmarked was the Platinum Medal awarded by the Institute of Metals in 1958 to the late Professor Robert Hutton, who was the first Director of the British Non-Ferrous Metals Research Association, at one time Goldsmiths’ Professor of Metallurgy at Cambridge and for many years Chairman of the Assay Office committee of the Goldsmiths’ Company. This was followed by a cup and cover designed and made by Miss Jocelyn Burton.
At a later ceremony the finished platinum cup was presented to the Goldsmiths’ Company jointly by Johnson Matthey and Rustenburg Platinum Mines.