|Hardness||4-5 along the cleavage plane and 6-7 across.|
|Crystal form||Triclinic. Forms long bladed crystals or radially aggregates.|
|Optical properties||Weak pleocroism.|
|Habitat||Appears only in highly metamorphic rocks, never in eruptive rocks. The crystals grows in quartz jugs that lies in the dark metamorphic schist.|
|Associates||Often with staurolite in the schist. Sometimes with beryl and rutil in the quartz jugs.|
|Notes||Looks like topas, but topas occurs in pegmatites, where
kyanite never exists.|
Polymorphs : Andalusite and Sillimanite
| To silicate index.
|| Mineral group index.
If you have some questions, suggestions or comments you are welcome to write me a line or two.