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Formula: CaMgMn3+3O2(PO4)2(CO3)F.5H2O
Hydrated phosphate-carbonate, manganese-bearing mineral
Crystal system: Monoclinic
Specific gravity: 2.76 measured, 2.756 calculated for the empirical formula
Hardness: 3
Streak: Pink
Colour: Dark red
Whiterockite is a new mineral, approved in 2020 and to date (July 2025) reported only from the type locality.
Localities
At the type locality, the White Rock No. 2 pegmatite, White Rock Feldspar Mine, Old Boolcoomata Station, Bimbowrie
Conservation Park, Pastoral Unincorporated Area, South Australia, the
pegmatite is a poorly outcropping
beryl–columbite phosphate
rare-element type pegmatite,
hosted by upper greenschist to
amphibolite facies metamorphosed rocks that are
overlain by metasediments.
The pegmatites are mineralogically zoned and characterised
by the occurrence of late-stage phosphate nodules between the quartz core
and intermediate feldspar-rich zone.
Triplite–zwieselite was
formed by
metasomatic alteration of magmatic fluorapatite and has been
transformed by hydrothermal alteration and weathering, in an oxidising, low-temperature and low-pH (acid)
environment, to give a complex, microcrystalline intergrowth of
secondary phosphate minerals. At White Rock,
triplite and associated
secondary phosphate minerals have been exposed only in the
No.2 quarry. Secondary phosphate minerals include
bermanite, bimbowrieite,
cyrilovite,
jahnsite-(NaFeMg),
jahnsite-(NaMnMg),
magnesiobermanite,
mitridatite, perloffite,
phosphosiderite,
strunzite and
ushkovite-laueite.
Whiterockite is found in cavities in a matrix comprising
fluorapatite and minor quartz.
Associated minerals include
dufrénite-natrodufrénite,
ushkovite, bermanite,
leucophosphite and
sellaite.
Whiterockite occurs as aggregates of crystals up to 0.7 mm across. Individual crystals are thin six-sided
plates up to 0.2 mm in width with a thickness of ∼1–2 μm. The mineral is dark red with a pink streak. The lustre is
vitreous and thin crystals are transparent. Whiterockite is brittle with an irregular fracture and one
perfect cleavage
(MM 89.1.127-132).
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