kyanite
noun
ky·a·nite ˈkī-ə-ˌnīt 
: an aluminum silicate mineral Al2SiO5 that occurs usually in blue thin-bladed triclinic crystals and crystalline aggregates
Word History
Etymology
German Zyanit, from Greek kyanos dark blue enamel, lapis lazuli
First Known Use
1794, in the meaning defined above