Strontium Sulfate

SrSO4

Strontium Sulfate - SrSO4
Chemical name
Strontium Sulfate
Mineral name
Coelestine
Chemical formula
SrSO4
Crystal system
orthorhombic
Crystal Class
orthorhombic-dipyramidal (2/m 2/m 2/m)
Space Group
Pnma
Unit cell
a [Å]:8.36
b [Å]:5.35
c [Å]:6.85
Molecular weight [g/mol]
183,68
Formula units
Z=4
Frequent crystal surfaces
{001}, {010}, {011}, {101}, {210}
Mohs hardness
3 - 3.5
Density [g/cm3]
3.9
Cleavage
perfect on {001}, indistinct on {210}
Fracture / Tenacity
brittle, uneven to conchoidal
Color
colorless, white, pale blue, pink, pale green, pale brown, black
Streak
white
Transparency
transparent to translucent
Luster
vitreous, pearly on cleavage surfaces
Optical character
biaxial (+)
Refractive Index
nα=1.619-1.622; nβ=1.622-1.624; nΥ=1.630-1.632
Birefringence δ
0.011
Pleochroism δ
weak