-
spherules Specific gravity F****
Density 3.97 (measured)
Optical properties Biaxal (-)
Refractive index nα = 1.638, nβ = 1.666, nγ = 1.682 2V
angle 73° (calculated)...
- axes. The two
classes of
minerals naturally become known as
uniaxal and
biaxal—or, in
later literature,
uniaxial and biaxial. In 1813,
Brewster observed...
-
Transparent Density 3.36 (calculated) (approximated)
Optical properties Biaxal (+)
Refractive index nα=1.54, nβ=1.63, nγ=1.59 (approximated) Pleochroism...
- yellow, grey-yellow
Streak White Diaphaneity Translucent Optical properties Biaxal (-)
Refractive index nα=1.74-1.75, nβ~1.76, nγ~1.76 (approximated) References...
-
Transparent Density 3.31 (calculated); 3.23 (measured)
Optical properties Biaxal (+)
Refractive index nα=1.50, nβ=1.51, nγ=1.52 (approximated) Pleochroism...
-
transparent Density 3.21 (calculated) (approximated)
Optical properties Biaxal (-)
Refractive index nα=1.51, nβ=1.55, nγ=1.56 (approximated) Pleochroism...
-
Diaphaneity Transparent to
translucent Density 3.97 (measured)
Optical properties Biaxal (+)
Refractive index nα = 1.60, nβ = 1.65, nγ = 1.72 (approximated) Pleochroism...
-
Subadamantine Streak White Diaphaneity Transparent Density 4.97
Optical properties Biaxal (-)
Refractive index nα=1.89, nβ=1.91, nγ=1.91 (approximated) 2V
angle ca...
-
Density 2.78 (measured); 2.84 (calculated; approximated)
Optical properties Biaxal (-)
Refractive index nα=1.58, nβ=1.60, nγ=1.61 (approximated) Pleochroism...
-
Diaphaneity Transparent Specific gravity 2.50 (measured)
Optical properties Biaxal (-)
Refractive index nα=1.51, nβ=1.51, nγ=1.52 (approximated) 2V
angle 83°...
