Cummingtonite
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Cummingtonite is a metamorphic amphibole with the chemical composition 25Si8O222, magnesium iron silicate hydroxide.
Fibrous, brownish crystals of cummingtonite – Locality: Dannemora Mine, Uppsala Län, Uppland, Sweden
Gedrite
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Gedrite is a crystal belonging to the orthorhombic ferromagnesian subgroup of the amphibole supergroup of the double chain inosilicate minerals with the ideal chemical formula Mg2O222.
Gedrite on a feldspar matrix
