Serpentine

1. ppl serpentine alteration x5

2. xpl serpentine alteration x5

group                                   phyllosilicate
system                                  monoclinic
formula                                 Mg3Si2O5(OH)4
optic                                   biaxial neg
Too-Vee                                 5 - 60¡ variable
relief.1                                low to mod low pos / neg
min. index                              1.529 / 1.604
color                                   colorless, green
pleochroism                             yes
birefringence.1                         0.001 - 0.010
cleavage                                yes
elongation                              yes
extinction                              parallel
angle                                   0¡
alteration                              chlorite, quartz, brown and yellow staining (from Mg)
habit.1                                 fibrous, tabular
occurence                               metamorphic (contact, carbonate), sedimentary, hydrothermal (mafic, ultramafic)
TwoV                                    1 2
relief                                  1 4
pleochroism.2                           yellow, green
birefringence                           1 2 3 4 
cleavage.2                              {001} perfect