idocrase
noun
ido·crase ˈī-də-ˌkrās 
ˈi-,
-ˌkrāz
: a mineral that is a complex silicate especially of calcium, magnesium, iron, and aluminum
Word History
Etymology
French, from Greek eidos form + krasis mixture, from kerannynai to mix — more at crater
First Known Use
1804, in the meaning defined above