Clinozoisite
Ca2Al3(Si2O7)(SiO4)O(OH)
Chemical name
Clinozoisite
Mineral name
Clinozoisite
Chemical formula
Ca2Al3(Si2O7)(SiO4)O(OH)
Crystal system
monoclinic
Crystal Class
monoclinic-prismatic (2/m)
Space Group
P2_1/m
Unit cell
a [Å]:8.88
b [Å]:5.58
c [Å]:10.16
Formula units
Z=2
Frequent crystal surfaces
{100}, {111}, {001}
Twinning
lamellar on {100}, rare
Mohs hardness
6.5 - 7
Density [g/cm3]
3.2 - 3.4
Cleavage
perfect on {001}
Fracture / Tenacity
uneven
Color
colorless, gray, green, light yellowish
Streak
grayish, white
Transparency
transparent to translucent
Optical character
biaxial (+)
Refractive Index
nα=1.670-1.718; nβ=1.670-1.725; nΥ=1.690-1.734
Birefringence δ
0.004 - 0.015
Pleochroism δ
if containing small quantities of Fe(3+) moderate