Old cut sapphires

[Snowdrop13]

An antique ring has caught my eye- normally I'm a big diamond fan but I thought this one looked interesting, and a nice colour. Can anyone tell me about old cut sapphires? Will they have had treatments or are they more likely to be natural? When do they date from?

 

[chrono]

It depends on how old the stone is. Since way back to Roman times, gemstones have been heated. Synthetic sapphires became the rage around the Art Deco period. Surface diffusion was present in the 1900s. Lattice diffusion came about only the last few decades.

 

[Snowdrop13]

Thanks, it's described as "early 20th Century". Wow, I didn't consider that it might be synthetic, guess the Art Deco period was a bit later?

 

[distracts]

Synthetic corundum has been used in jewelry since the 1880s. The art deco period was CRAZY about synthetic sapphires and rubies - when looking at an art deco piece with corundum, I assume it is synthetic unless there is a lab report stating otherwise. I do, however, consider synthetic/questionable stones to be acceptable in period pieces at higher prices than I would in modern pieces, though obviously still at a lesser price than natural stones, if they are original to the piece. An early 20th century ring would definitely be a good contender for possibly being synthetic. Less likely if it was from, say, pre-1910, more likely if it was from the 1920s.