Hi Debbie thank you for writing in with the following hallmark question:
"I've recently inherited my great grandmother's amethyst ring and wanted to know what the markings mean please. I have a fair idea but not quite sure. I would appreciate your help please. It says; 9 .375 then an anchor on it's side R SYN/ST"
OK Debbie. The 9 is the carat marking, the millesimal value is the equivalent you can see next door. The decimal point before the 375 tells us the ring is dated between 1931 and 1975.
The anchor mark is the UK assaying office of Birmingham. The R is the date letter. If you look up the date letter against the Birmingham date letter chart you will find the Date letter will be within 1931 and 1975. You have to be meticulous here and make sure everything exactly matches, even the stamp mark behind the letter.
SYN/ST probably is disclosing the fact that the amethyst is a synthetic stone. Synthetic stones will usually have more life than natural stones. If you have a magnifying glass or jewelers loupe and familiar with what the jeweler's loupe can tell you you might also notice the color zoning or lack of color zoning. Zoning or color variances especially in the amethyst, is indication of a natural gemstone.
