|
|
Aragonite |
Calcite |
Dolomite |
|
Crystal System |
Orthorhombic |
Trigonal |
Trigonal |
|
Indicatrix |
Biaxial (-) 2V = 18o |
Uniaxial (-) |
Uniaxial (-) |
|
Refractive index |
nx = 1.530 ny = 1.681 nz = 1.685 |
no =1.658 ne = 1.486 |
no = 1.679 ne = 1.500 |
|
Birefringence |
0.155 |
0.172 |
0.179 |
|
|
Anhydrite |
Gypsum |
Quartz |
|
Crystal System |
Orthrhombic |
Monoclinic |
Trigonal |
|
Indicatirx |
Biaxial (+) 2V = 44o |
Biaxial (+) 2V = 58o |
Uniaxial (+) |
|
Refractive index |
nx = 1.570 ny = 1.576 nz = 1.614 |
nx = 1.519-1.521 ny = 1.522-1.526 nz = 1.529-1.531 |
no = 1.544 ne = 1.553
|
|
Birefringence |
0.044 |
0.010 |
0.009 |
|
|
Barite |
Celestite |
Siderite |
|
Crystal System |
Orthorhombic |
Orthorhombic |
Trigonal |
|
Indicatrix |
Biaxial (+) 2V = 36-40o |
Biaxial (+) 2V=51o |
Uniaxial (-) |
|
Refractive index |
nx = 1.634-1.637 ny = 1.636-1.639 nz = 1.646-1.649 |
nx = 1.621-1.622 ny = 1.623-1.624 nz = 1.630-1.632 |
no = 1.875 ne = 1.633 |
|
Birefringence |
0.012 |
0.009-0.010 |
0.242 |