Questionhi: I recently saw a platinum filigree ring with diamonds that was in the Edwardian style. it was marked "900 Plat 100 Irid".
the diamonds appear to be newer cuts than old European or old mine cut. my question is to know if i can help date the ring by the mark? do you know when they began using that mark?
thanks !
AnswerG'day Nancy and many thanks for your query.
Sounds like a reproduction item set with Brilliant Cut Diamonds. They can be very attractive though - as long as you understand it is NOT Edwardian.
It's only recently (say over the past 25 years) that the PLAT mark indicating pure platinum had been turned into an alloy by mixing other metals.
Different countries started using it earlier with others later, so there is no FIXED date when this occurred. Just generalize.
In this case the 900 Plat is the International decimal mark showing the quality in parts-per-thousand. So it has 900 parts of pure platinum mixed with 100 parts of Iridium
You might also like to add this query to my blog at http://how2valuejewelry.com/ as other may have had a similar problem. Can't hurt anyway and who knows what answers you may get.
Hope this helps...
