Ruby have foreign material in surface reaching fractures

[OTL]

Please someone enlighten me, I was shopping around for rubies and found this uneated ruby, it is certified no heat, but have foreign materials in surface reaching fractures. I thought foerign materials such as lead glass need heating to be filled in. Is there something I missed?

Thanks in advance!

 

[cm366]

"Heat' is probably being used to describe temperatures high enough to change the crystal structure and dissolve inclusions such as rutile silk. There's no way I'm aware of to identify whether corundum has been heated to, say, 200 degrees - and there isn't typically any benefit from doing so because you don't get the changes in colour or clarity from high heat. There are a few papers floating around about benefits from heating at only 350 C or so, and you'll sometimes see those stones sold as 'traditional low heat only' or similar, but your lab might mean the 1300-1800 degree bake.

Foreign materials would also include things like plastic resins or even oil, which certainly don't need much heat to be applied....

 

[chrono]

I don't think oil or resin needs high heat or even heat to coat any surface reaching fractures. Oil is typically applied under vacuum but I'm not as sure about the method of application for resins, especially since there are many different types of resins.