Calcium Sulfate
Ca(SO4)*2H2O
|
Chemical name
Calcium Sulfate |
|
Mineral name
Gypsum |
|
Chemical formula
Ca(SO4)*2H2O |
|
Melting point [°C]
128 |
|
Crystal system
monoclinic |
|
Crystal Class
monoclinic-prismatic (2/m) |
|
Space Group
A2/a |
|
Unit cell
a [Å]:6.52 b [Å]:15.18 c [Å]:6.29 |
|
Molecular weight [g/mol]
172.17 |
|
Formula units
Z=4 |
|
Frequent crystal surfaces
{010} |
|
Twinning
very common on {001}, contact twins |
|
Mohs hardness
2 |
|
Density [g/cm3]
2.3 - 2.4 |
|
Cleavage
perfect on {010}, distinct on {100} |
|
Fracture / Tenacity
flexible, inelastic, conchoidal on {100}, splintery parallel to [100] |
|
Color
colorless to white, yellow, tan, blue, pink, brown, reddish brown, gray |
|
Streak
white |
|
Transparency
transparent to translucent |
|
Luster
vitreous to silky, pearly, waxy |
|
Optical character
biaxial (+) |
|
Refractive Index
nα=1.519-1.521; nβ=1.522-1.523; nΥ=1.529-1.530 |
|
Birefringence δ
0.010 |
|
Pleochroism δ
none |
