Page 232 - A Practical Introduction to Optical Mineralogy

Appendix A.3 Refractive indices
of negative uniaxial minerals
1.4 1.5 1.54 1.6 1.7 1 8 1.9
topaz -
zeolites - - Silicates I 4 I 5 I 6 I 7 I 8 I 9
feldspathoid family
nepheline -
Non-silicmes
melilite group
carbonates
akermanite
aragonite
scapolite
sulphates silica group
-
barite cristobalite
celestite - tourmaline
gypsum - vesuvianite -
an hydrite
- r-
wolframite Non-silicates
2. 15-2.44 --
carbonates
calcite
dolomite
siderite
Appendix A.2 Refractive indices rhodochrosite
corundum
of positive uniaxial minerals apatite

Silicates 14 I 5 I 6 I 7 I 8 I 9 20 Appendix A.4 Refractive indices
beryl -
of isotropic minerals
feldspathoid family
Jeucite
Silicates 14 I 5 16 I 7 1 8
melilite group 19
gehlenite - feldspathoid family
silica group (Jeucite)
quartz - soda lite
analcime
zircon
garnet group
Non-silicates Non-silicates
sphalerite
cassiterite r spinel group - 2.4
rutile 2.6-2.9 ... (transparent members)
-
brucite fluorite
halite