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Formula: CaMn2+Zn2Fe3+2(PO4)sub>4(OH)2.8H2O
Hydrated phosphate containing hydroxyl, jahnsite subgroup,
jahnsite group,
Specific gravity: 2.87 calculatedZnFe3+
2
(PO4
)2
(OH)2
·6.5H2O
Colour: Yellow, brown
Environments
Jahnsite-(CaMnZn) is a relatively new mineral, approved in 2019 and to date (July 2022) reported only from the
type locality.
Localities
At the type locality, the 67 m level, Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District,
Upper Palatinate, Bavaria, Germany, jahnsite-(CaMnZn) forms as thin yellow crusts and brown epitactic growths on
altered phosphophyllite, both of which comprise lath-like crystals up
to 100 μm long. The crystals contain intergrowths of jahnsite-(CaMnZn) and
jahnsite-(CaMnMn) on a scale of ~50 μm
(MM 84.547-553).
The jahnsite-(CaMnZn) was found in an oxidized nodule of former
triphylite, now replaced by
phosphophyllite. It is a low temperature,
secondary mineral formed by alteration of
primary phosphates in a zoned
granitic
pegmatite. Associated minerals include
chalcophanite, hopeite,
jahnsite-(CaMnMn), zinc-bearing
laueite,
scholzite-parascholzite,
parahopeite, schmidite,
stewartite, vivianite,
whitmoreite-earlshannonite,
zincostrunzite and apatite
(HOM).
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