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

Metamorphic environments


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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