Clinozoisite - Encyclopedia
Class : Silicates
Subclass : Sorosilicates
Crystal system : Monoclinic
Chemistry : Ca2Al3(SiO4)3(OH)
Rarity : Uncommon
Clinozoisite belongs to the epidote group. It is a dimorph of zoisite which is found in the same deposits as epidote : low to medium grade metamorphic rocks, and calcic rocks subject to contact metamorphism. Its name is linked to its monoclinic structure and its chemical relationship with zoisite. Clinozoisite forms elongated to acicular prismatic crystals, with deeply longitudinally striated prismatic faces, often grouped in radiated masses. The color is white, gray, greenish, sometimes pinkish or pistachio green, exceptionally red. The transparent varieties are cut for jewelry.
Main photo : Clinozoisite from Alchuri, Gilgit-Baltistan, Pakistan © Lopatkin Oleg
Clinozoisite in the World
Twinning
A lamellar twin is known on {100}.
Fakes and treatments
No fake identified for this mineral species.
Hardness : 7
Density : 3.3 to 3.4
Fracture : Irregular
Streak : Gray-white
TP : Translucent to transparent
RI : 1.706 to 1.735
Birefringence : 0.006 to 0.011
Optical character : Biaxial +
Pleochroism : Visible
Fluorescence : None
Solubility : -
Magnetism : Paramagnetic
Radioactivity : None