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Mineralpedia Details for Gatehouseite

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Gatehouseite

Gatehouseite

Named for Dr. Bryan Michael Kenneth Cummings Gatehouse who was a crystal chemist at Monash University in Melbourne, Australia. Gatehouseite is a rare mineral which has its type and only locality at the Iron Monarch open cut in South Australia. There, it occurs “as a secondary mineral in cavities in a sedimentary Fe-Mn deposit, probably formed by reaction of phosphate-rich fluids with hausmannite at low temperature.

 Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/gatehouseite.pdf

Formula
Mn2+5(PO4)2(OH)4 
Crystal System
Orthorhombic 
Cleavage
Good, None, None 
Luster
Adamantine 
Color
yellow, yellow, pale orange 
Streak
light yellow 
Class
Orthorhombic - Disphenoidal 
Hardness
WebMineral
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Mindat
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Gatehouseite from Iron Monarch mine, Iron Knob, South Australia, Australia

Gatehouseite
            from Iron Monarch mine, Iron Knob, South Australia, Australia
Special Info
Type Locality

At least four good rosettes of Gatehouseite, an extremely rare anhydrous manganese phosphate. Discovered in 1993 and has yet to be discovered elsewhere. Gatehouseite probably forms in the presence of phosphate rich solutions acting upon manganese or iron rich sedimentary fluids under low temperatures. On this specimen there are also tiny, rice shaped crystals of Rhodochrosite. Gatehouseite was first described in Mineralogical Magazine, June /993, Vol. 57. It is named in honor of Bryan Gatehouse, an expert crystal chemist on oxide and oxysalts at Melbourne.

Orange brown micro crystals of Gatehouseite

Click thumbnail images for larger view.

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