Page 231 - A Practical Introduction to Optical Mineralogy

Appendix A.1 Refractive indices
of biaxial minerals

1 4 1 5 1 54 1 6 1 7 1 8 1 9
Silicates I 4 I 5 1 54 1 6 1 7 I 8
humite group
amphiboles
norbergite -
anthophyllite-gedrite chondrodite
humite ---
tremolite-ferroactinolite clinohumite
the hornblende series
mica group
glaucophane-riebeckite
phlogopite - f--
richterite biotite
katophorite -- muscovite --
oxyhornblende
kaersutite lepidolite - ,----
paragonite -
-- glaucomte 1---
eckermannite
arfvedsonite -I- olivine group
Fa
forsterite 0
Al 2 Si0 5 polymorphs fayalite } F ol,,
-
andalusite pumpellyite
kyanite - pyroxene group
sillimanite -
enstatite---orthoferrosilit e opx
chlorite diopside- hedenbergite
chloritoid - di,,
augite
clay minerals pigeonite
kaolin - - -
aegirine
illite ~
aegirine- augite
montmorillonite
jadeite --
cordierite - f-- spodumene
epidote group -
wollastonite --
zoisite
clinozoisite - serpentine +-
epidote - silica group
tridymite -
feldspar group
K feldspars - } alkali feldspars sphene -
Na feldspars (albite) - - } ,,,,,,"T ''"'''" staurolite -
Ca feldspars (anorthite) talc