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Formula: Ca2SiO3(OH)F.H2O
Nesosilicate (insular SiO4 groups)
Specific gravity: 2.73
Hardness: 4½
Streak: White
Colour: Colourless, pink
Solubility: Gelatinised by acids
Common impurities: B,Al,Na,P
Environments
Localities
At the Shijiang Shan-Shalonggou mining area, Inner Mongolia, China, the mineral deposits occur predominantly in
veins of hydrothermal origin in skarn. Bultfonteinite was originally
found as pink-tinted and opaque clusters 3–6 mm across, attached to blocky
calcite crystals. Specimens showing spectacular hemispherical sprays of
acicular bultfonteinite to 4 cm in diameter on massive andradite
matrix were found later
(R&M 96.5.399-400).
At the Fuka mine, Fuka, Bicchu-cho, Takahashi City, Okayama Prefecture, Japan, the deposit is a high-temperature,
boron-containing skarn
(R&M 965.395). Bultfonteinite is associated with
oyelite, scawtite and
xonotlite
(HOM).
At the N'Chwaning II mine, Kuruman, Kalahari manganese field, Northern Cape, South Africa, acicular bultfonteinite
to 1 cm is associated with crystals of poldervaartite to 8 mm
(AJM 10.1.37).
At the type locality, the Bultfontein mine, KEM JV Mine, Kimberley, Sol Plaatje, Frances Baard, Northern Cape, South Africa,
bultfonteinite was found in a large mass of dolerite and
shale fragments in a kimberlite
pipe, associated with calcite, apophyllite
and natrolite
(AM 18.32, HOM).
At the Commercial Quarry, Sky Blue Hill, Crestmore quarries, Crestmore, Riverside county, California, USA, bultfonteinite
occurs in a contact zone in thermally metamorphosed
limestone, associated with afwillite
and scawtite
(AM 40.900-904, HOM).
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