I'm fairly certain that the stone is synthetic and not worth very much. I suspect that it may not be the stone that was originally set in the ring, and your opinion that the stone may have been made between 1930 and 1960 seems to confirm my suspicion. The main thing of importance to me is the age and origin of the setting itself.
I will continue my research and thank you again for your assistance.
PG
Rating
Russian Hallmarks by: Elkan
the stone is set upside down indeed. Most probably synthetic corundum but what sort of synthetic stone it doesn't matter as the value of synthetic stones is never substantial.
To mention that it is "laced with vanadium" is new to me, I don't think this is of any relevancy.
It's a Russian hallmark that was used since ± 1860 but the ring and stone appear to be made somewhere between the 1930's and 1960's.
