Ottrelite
Ottrelite
(n.)
A micaceous mineral occurring in small scales. It is characteristic of certain crystalline schists.
Webster's Revised Unabridged Dictionary (1913), edited by Noah Porter.
About
Ottrelite

General Information:

Chemical Formula:
(Mn,Fe++,Mg)2Al4Si2O10(OH)4
Physical Properties:

Cleavage:
[???] Good

Color:
pistachio green.

Density:
3.52

Hardness:
6-7 - Orthoclase-Quartz
More details...