Whiteite-(MnMnMg)

minerals

triploidite

rhodochrosite

hausmannite

Formula: Mn2+Mn2+Mg2Al2(PO4)4(OH)2.8H2O
Hydrated phosphate containing hydroxyl, jahnsite group, whiteite subgroup
Specific gravity: 2.61
Hardness: 4
Streak: Pale orange
Colour: Reddish orange
Environments

Sedimentary environments
Hydrothermal environments

Localities

The type locality, the Iron Monarch open cut, Iron Knob, Middleback Range, Eyre Peninsula, South Australia, lies within an iron formation composed primarily of iron carbonate, silica, and iron oxide, with primary iron silicates such as iron-rich talc and cummingtonitegrunerite. The orebody contains pods of high-grade manganese ore. Whiteite-(MnMnMg) was collected from a manganese-rich, carbonate-rich zone, comprising hematite, hausmannite, baryte, manganese-rich calcite and rhodochrosite. Carbonate-rich veins host a number of secondary phosphate, arsenate, vanadate, and sulphate minerals that formed as late-stage, low-temperature hydrothermal phases. An unusual feature of the secondary minerals from this zone is that many of them contain no Fe, even those that would readily accommodate it, such as collinsite, fairfieldite, gatehouseite, arsenoclasite, triploidite, waterhouseite and whiteite-(MnMnMg). This suggests that the source of the hydrothermal fluids from which these minerals crystallised was a region with a low concentration of Fe (CM 57(2).215-223).
The whiteite-(MnMnMg) was found as a single unterminated prismatic crystal associated with triploidite and rhodochrosite (Mindat).

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