Epidote

1. ppl epidote x20

2. xpl epidote x20

ppl two cleavages 20*

xpl zoned diopside 20*

ppl filling of vessicles 5*

xpl anomolous inter. colors 5*

ppl porphyroblastic augen 5*

xpl pressure shadows 5*

xpl 5*

group                                   epidote
system                                  monoclinic
formula                                 CA2Fe3+Al2O(Si2O7)(SiO4)(OH))
optic                                   biaxial neg
Too-Vee                                 64 - 90¡
relief.1                                high pos
min. index                              1.715 / 1.797
color                                   colorless, green, yellow
pleochroism                             yes
birefringence.1                         0.012 - 0.049
cleavage                                yes {
elongation                              yes
extinction                              inclined
angle                                   25 - 40¡
alteration                              not readily altered (detrital grains in clastic sediments)
habit.1                                 tabular, granular, columnar
occurence                               igneous (accessory), hydrothermal, metamorphic (medium grade)
TwoV                                    2
relief                                  3
pleochroism.2                           yellow, green
birefringence                           5 6 7 8 9 10 11 12 13 
cleavage.2                              {001} perfect basal, {100} poor