Clinoenstatite - Encyclopedia
Class : Silicates
Subclass : Inosilicates
Crystal system : Monoclinic
Chemistry : MgSiO3
Rarity : Rare
Clinoenstatite belongs to the group of pyroxenes. It is a rare dimorph of enstatite which forms a continuous series with clinoferrosilite. Its name is related to its monoclinic crystal system and its chemical similarity to enstatite. It is found in short to tabular prismatic crystals of 2 mm at most, frequently twinned, and in lamellar masses in rare magnesian andesites, in ultrabasic diopside rocks and hornfels with a strong metamorphic gradient. On the other hand, it is an essential constituent of chondrites and achondrites. Clinoenstatite is usually brown to greenish gray.
Main photo : Clinoenstatite from the alluvial deposits of Dordogne, Puy-de-Dôme, France © François Périnet
Clinoenstatite in the World
Twinning
Polysynthetic twins on {100} are known for this mineral species.
Fakes and treatments
No fake identified for this mineral species.
Hardness : 5 to 6
Density : 3.21
Fracture : Conchoidal
Streak : White
TP : Translucent to transparent
RI : 1.651 to 1.660
Birefringence : 0.009
Optical character : Biaxial +
Pleochroism : Visible
Fluorescence : None
Solubility : Insoluble
Magnetism : None
Radioactivity : None