Arsen Sulfide
As2S3
Chemical name
Arsen Sulfide |
Mineral name
Orpiment |
Chemical formula
As2S3 |
Melting point [°C]
300 - 325 |
Crystal system
monoclinic |
Crystal Class
monoclinic-prismatic (2/m) |
Space Group
P2_1/n |
Unit cell
a [Å]:11.48 b [Å]:9.58 c [Å]:4.26 |
Molecular weight [g/mol]
246,06 |
Formula units
Z=4 |
Frequent crystal surfaces
{100}, {010}, {301}, {110}, {011}, {210} |
Mohs hardness
1.5 - 2 |
Density [g/cm3]
3.49 |
Cleavage
perfect on {010}, imperfect on {100} |
Fracture / Tenacity
sectile |
Color
yellow to golden or brownish-yellow |
Streak
pale lemon-yellow |
Transparency
transparent |
Luster
resinous, pearly on cleavage surfaces |
Optical character
biaxial (-) |
Refractive Index
nα=2.400; nβ=2.810; nΥ=3.020 |
Birefringence δ
0.620 |
Pleochroism δ
strong |
Piezoelectric crystals |
T(c) [°C]
nω = 1.564–1.595, |