Gatehouseite, a new manganese hydroxy phosphate from Iron Monarch, South Australia

The new mineral occurs as radiating clusters of pale yellow, and yellow to pale brownish orange bladed crystals up to 100 μm in length. It also occurs as overgrowths on prismatic arsenoclasite crystals. Associated minerals are baryte, shigaite, manganoan ferroan calcite, hausmannite and hematite. Gatehouseite appears to have formed at low temperature by the interaction of phosphorus-rich fluids on hausmannite in carbonate-rich fractures in the hematite ore. Crystallographic and compositional data are presented. -from Authors