We would very much like to see a photo of this mark as there have been a number of enquiries. All I can tell you at this stage, is probably what you already know. The number 950 is the UK compulsory mark for Platinum. The assay office mark is most likely the mark you think is a shield. What's inside the shield is crucial info. If you could upload a photo of the mark in a follow-up submission it would help our research.
I have the same letters inside a platinum ring bought in a general second-hand shop in Edinburgh. The ring is platinum with two different 950 marks. There's a shield-shaped mark that I can't see well. Also ATL, then a smaller D. The letters are raised inside a rectangular depresseion with rounded edges. The style of the ring is modern.
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More Information Requested. by: Anonymous
Hi Alex, there is not sufficient info for research. Are there dots between the letters? Are the letters in little boxes? If yes, what shape are the boxes behind the letters? What is the item of jewelry? How old do you think it is?
Can you upload a photo of the mark in a follow-up submission?