Tourmaline 
This slide shows zoned trigonal cross-sections and elongate sections. Note green to brown pleochroism. Tourmaline may also display bluish pleochroism.
UNC sample
?
Rock type
unknown
Locality
unknown
Tourmaline This slide shows zoned trigonal cross-sections and elongate sections. Note green to brown pleochroism. Tourmaline may also display bluish pleochroism. |
UNC sample ? | |
Rock type unknown | ||
Locality unknown | ||
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