Andre Vassort, a diamond, rock crystal, turquoise and onyx ring, France, circa 1955 set with a carved rock crystal between two rows of graduated round brilliant-cut diamonds, further enhanced with carved turquoise and onyx shoulders, with Andre Vassort maker's mark and French assay marks, estimated total diamond weight 2.50 carats, mounted in 18ct gold, ring size K1/2. Little is known the French jeweller Andre Vassort, which is so often the case with the craftsmen and workshops behind the famous Maisons of the place Vendôme. All around Paris, tucked away in discreet buildings, skilled and highly creative master craftsmen worked anonymously for their high profile clients. His maker's mark can be found sparingly on jewels for Cartier, Boucheron and van Cleef & Arpels. He worked from the 1950s, often experimenting with the use of 18 carat yellow gold and coloured gemstones.