Heat used in setting jewelry changing color of sapphire?

[Blue-Seeker]

This may be a silly newbie question. If so, I apologize. But I'm wondering if the heat from a jeweler's tools (welder? torch?) when setting a stone is hot enough to actually change the color of an unheated sapphire? Thank you

 

[TheDoctor]

Heat needn't be used when setting a sapphire, as it's really not necessary. The metal is worked cold.
Indirect torch heat won't affect the unheated status of a natural stone, but direct heat is a large risk and should be avoided.

 

[Edward Bristol]

Correct. A passing torch does no harm.

 

[gsellis]

Sapphires have to cook hot to change. Ms Elser may have the recipe and maybe she can comment. But I think it is 600C for a few hours. I don't have a kiln, so cannot comment authoritatively. But I have a view untreated Yagos that would probably go blue after a 'sauna'.

 

[Blue-Seeker]

Thank you for your replies, everyone. I truly learn something new every day reading this forum.