Formula: PbMn2+2Fe3+2(PO4)3(OH)3
Phosphate, bjarebyite group, manganese-bearing mineral
Crystal System: Monoclinic
Specific gravity: 4.416 calculated
Hardness: 4
Streak: Pale orange
Colour: Brownish orange


Plumboperloffite is a new mineral, approved in 2020 and to date reported only from the type locality.


At the type locality, the Wiperaminga Hill West Quarry, Boolcoomatta Reserve, Olary Province, South Australia, pegmatites were exploited for feldspar, beryl and muscovite between 1957 and 1980. The pegmatites occur near the base of a prominent range of hills which comprise banded quartzmica gneiss and schist of the Early to Middle Proterozoic age (2.5 to 1.0 billion years ago). The metasediments have been granitised and in many places are intruded by granite and associated pegmatite and aplite bodies. The pegmatites are mineralogically zoned and comprise an outer border zone of fine- to medium- grained microcline, quartz, plagioclase and muscovite, an intermediate zone of coarse-grained muscovite, quartz, microcline, plagioclase, beryl and apatite (and triplite), and an inner quartz core or cores. The Wiperaminga Hill pegmatites belong to the berylcolumbite–phosphate rare element type. Phosphate minerals, dufrénite, florencite, apatite, triplite, dickinsonite and barbosalite have been reported from this locality.
In 2018 masses of orange to dark brown triplitezwieselite were found on the dumps of the eastern quarry. Secondary phosphate minerals have formed in seams and cavities in the triplitezwieselite by hydrothermal alteration and weathering, in an oxidising, low temperature, low-pH (very acid) environment.
Plumboperloffite occurs in a single cavity in a matrix comprising triplite, barbosalite and minor quartz. Associated minerals are fluorapatite, phosphosiderite, natrodufrénite and fluorite. Plumboperloffite occurs as thin tabular to bladed vitreous crystals, with a brownish-orange colour. Individual crystals are up to 40 μm in length (MM 88.2.170–175).

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