1) Orthorhombic mineral 
Gedrite is a crystal belonging to the orthorhombic ferromagnesian subgroup of the amphibole supergroup of the double chain inosilicate minerals with the ideal formula: Mg2(Mg3Al2)(Si6Al2)O22(OH)2 Gedrite is the magnesium (Mg) rich endmember of a solid solution series, with divalent magnesium cations readily replaced with ferrous iron (Fe), leading...