Bytownite
An70-An90
Chemical name
Bytownite
Mineral name
Bytownite
Chemical formula
An70-An90
Crystal system
triclinic
Crystal Class
Pinacoidal
Space Group
I1
Unit cell
a [Å]:8.178
b [Å]:12.870
c [Å]:14.187
Mohs hardness
6 - 6.5
Cleavage
(001) perfect, (010) good, (110) imperfect
Fracture / Tenacity
Uneven to conchoidal
Color
Colorless, white, gray
Luster
Vitreous, pearly on cleavages
Refractive Index
nα = 1.563-1.572,
nβ = 1.568-1.578,
nγ = 1.573-1.583
nβ = 1.568-1.578,
nγ = 1.573-1.583
Birefringence δ
0.010 - 0.011
