hi e1. Hope you guys are enjoying the weekend I got this 11.7mm stone in a lot of vintage jewelry from the 59’s and a tad earlier. I normally would have tossed it aside but the presidium was on and ready. It jumps right to ruby and fluorescences under my UV light. I was trying to read on the fluorescence phenomena and I thought it was because the stone was heat treated. I need to read up some more from other sources to understand it better it is flawless as far as I can tell so I am assuming this big guy is lab or synthetic I know true tester doesn’t know the difference I was just wondering if these stones had any type of decent value. anyone have any info to share? It would be very much appreciated. Thank you in advance
Rubies fluoresce due to the chromium content, lab grown rubies tend to have less iron (which subdues the fluorescence in natural rubies), so they glow more strongly. Lab grown (synthetic is the same as lab grown) aren't usually heat treated as they are grown to be the colour required to start with. Heat treating can improve the colour of natural rubies. On it's own as a synthetic ruby it's not worth much, but keep it to set into a piece of jewellery missing a similar stone and it will add much more value than the stone being sold on it's own.
Lab rubies generally glow more orangey-red - red than the sought after high chromium content Burmese rubies, which have a fuchsia hue to their red fluorescence. As Ce said, most other natural rubies have a higher iron content, which subdues fluorescence.