Jarosewichite

jarosewichite

cahnite

flinkite

hausmannite

Images

Formula: Mn3+Mn2+3(AsO4)(OH)6
Anhydrous arsenate containing hydroxyl, chlorophoenicite group, manganese-bearing mineral
Crystal System: Orthorhombic
Specific gravity: 3.66 measured, 3.70 calculated
Hardness: 4
Streak: Reddish orange
Colour: Dark red
Common impurities: Mg
Environments:

Metamorphic environments

To date (November 2024) the type locality, the Buckwheat pit, Franklin Mine, Franklin Mining District, Sussex county, New Jersey, USA, is the only recorded locality for jarosewichite.
The type specimen was collected on the dumps; it consists of massive andradite intergrown with franklinite. The ore is vuggy and the vugs are lined with a druse of an unknown mineral. Upon the druse are tiny crystals of hausmannite, cahnite and allactite. The cahnite is coated with flinkite and jarosewichite, which appear to have formed at the same time. Some jarosewichite encrusts flinkite, indicating it was the last phase formed (AM 67.1043-1047).
Jarosewichite from the Buckwheat pit - Image

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