I have a small star sapphire and I wanted to make it into a ring using the Art Clay Silver. The gem chart that lists the characteristics of gemstones and indicates which ones are safe to fire in a kiln, lists normal sapphires but it doesn't list star sapphires. Is it safe to fire them in place or do they need to be set after the piece has been fire?
It isn't safe to fire star sapphires in a kiln as they will crumble to dust due to the extreme heat and nature of a star sapphire. You will need to create your design so the stone can be set after the piece is fired.