Childrenite

phosphate

crandallite

Formula: Fe2+Al(PO4)(OH)2.H2O
Hydrated phosphate containing hydroxyl, forms a series with eosphorite
Specific gravity: 3.11 to 3.19
Hardness: 5
Streak: White
Colour: Yellowish brown, brown, clove-brown; colourless in transmitted light.
Solubility: Soluble in acids.
Environments:

Pegmatites
Hydrothermal environments

Childrenite occurs in some complex granite pegmatites; it is typically a low-temperature hydrothermal alteration product of primary phosphate minerals (HOM). Associated minerals include apatite, goethite, siderite and tourmaline (Mindat).

At Tom's quarry, South Australia, childrenite lines cavities in variscite and crandallite and forms an intergrowth with beryl (AJM 17.1.14).

At Llallagua, Bolivia, childrenite is often found without associated species, but it also has been found encrusting paravauxite, wavellite or vivianite (MinRec 37.2.131).

At Greifenstein, Erzgebirge District, Saxony, Germany, childrenite is associated with zinnwaldite (a series between siderophyllite and polylithionite), tourmaline, apatite and kaolinite (HOM).

At the Trepča Stan Terg mine, Kosovska Mitrovica, Kosovo, childrenite occurs with its alteration product, crandallite, associated with siderite, ankerite, rhodochrosite, quartz and sometimes vivianite. Some childrenite crystals have inclusions of boulangerite (MinRec 38.4.281).

At St Austell, Cornwall, England, UK, childrenite occurs with zinnwaldite, tourmaline and apatite (Dana).


At the type locality, Tavistock, Devon, England, UK, childrenite occurs in low temperature hydrothermal veins, associated with siderite, quartz, pyrite and fluorapatite (Mindat, HOM, Dana)

At the Chickering mine, Walpole, Cheshire county, New Hampshire, USA, childrenite is one of the commonest secondary phosphate minerals. It is found in late-stage, triphylite replacement cavities, associated with siderite, apatite, strunzite, quartz, and albite (R&M 90.5.414).

Common impurities: Ca,Mn

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