Today I received a Ruby from Thailand, it was a .6 carat with a dark inclusion, I took a spectrum of the stone and use the companion software from Goylab to compare this stone to a known synthetic ruby and my as mentioned pendant purchase.
The spectrum or chart shows a large absorption at around 536nm for the , ruby an this d not for the Thailand ruby this has been consistant in all my tests so far,
My pendant purchase again shows not large absorption in the 536nm region which I believe shows this to be a natural ruby but I will do a specific gravity when I unmount the gem.