Cummingtonite from lead mining district Lawrence county South Dakota USA
Size-
6.2cm x 3.1cm x 2.8cm
Weight-
63g
You will receive the item in the photo
Cummingtonite is a magnesium iron inosilicate amphibole mineral.
Crystal system-Monoclinic. It frequently appears in radiating fibrous or acicular (needle like) crystal habits.
Mineral class- Silicates. Specifically the inosilicate subclass and amphibole group.
Rock formation- commonly found in regionally metamorphic rocks. It typically occurs in magnesium rich amphiboles, metamorphosed mafic volcanic rocks, and banded iron formations, where it frequently coexists with minerals like hornblende,garnet,magnetite and quartz.
It measures 5-6 on the MOHs hardness scale.
