Rutile

xpl 5*

ppl 10*

group                                   oxide
system                                  tetragonal
formula                                 TiO2
optic                                   uniaxial neg
Too-Vee                                 0¡
relief.1                                high pos
min. index                              2.61 / 2.90
color                                   red, brown, opaque
pleochroism                             no
birefringence.1                         0.009 - 0.010
cleavage                                yes
elongation                              yes
extinction                              parallel
angle                                   0¡
alteration                              rarely titanite, leucoxene
habit.1                                 acicular, bladed, prismatic
occurence                               igneous (accessory), metamorphic (accessory)

TwoV                                    
relief                                  3
pleochroism.2                           
birefringence                           1 4
cleavage.2                              {110} prismatic, {100} fair