About heating stones

Hi,
Was wondering if any one knew which stones can handle 225 Farenheit for 1/2 hour.
THE REASON...I've started working with polymer clay, and you have to bake it. I would love to make pieces with amathyst, jade, rhodenite and other stones baked right in..but I don't want to rune the stones...
Any suggestions would be helpful

Category: Gemstones Divination

Hi,
I don't know if you can heat the stones, but I was thinking maybe you can make the indentations before baking and afterwards just glue the stones onto the baked clay. This way you don't have to heat the stones.
Just a thought!

You need to find out which stones will change colors when heated. Amathyist will turn yellow this is how they make citrine. If a clear cyrstal has any additives like iron or such that you can not see they will color it under heat. It all depends on what is in the stone.
Best regards!