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
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