The close association of this mineral with cassiterite leads to its usefulness in locating tin-bearing pegmatites. Formed from the reaction of fluorine vapor with eutectic granites, where it occurs in
The close association of this mineral with cassiterite leads to its usefulness in locating tin-bearing pegmatites. Formed from the reaction of fluorine vapor with eutectic granites, where it occurs in cavities, its prismatic habit and orthorhombic crystallography derive from independent silica tetrahedra that cross-link its octahedral chains of aluminum hydroxide and fluoroxide. Named for a Red Sea island, FTP, what is this mineral with formula Al2SiO4(F,OH) and a Mohs Hardness of 7, the birthstone of November?
The close association of this mineral with cassiterite leads to its usefulness in locating tin-bearing pegmatites.
topaz