Let's Talk Gemstones:
Let's Talk Gemstones: Kyanite By Edna B. Anthony, Gemologist. My previous article initiated a series on polymorphic aluminum silicate gemstones, beginning with andalusite, following with kyanite (disthene) and ending with sillimanite (fibrolite). Andalusite, kyanite, and sillimanite all contain identical amounts of aluminum, silicon, and oxygen, combined with other trace elements. I find it