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Formula: Mn2+3(Mn2+,Mg,Fe3+,Al)42(As3+O3)2(As5+O4)4[(Si,As5+)O4]8(OH)42
Compound arsenate containing hydroxyl,
manganese-bearing mineral
Crystal System: Trigonal
Specific gravity: 3.620 calculated
Hardness: 3
Streak: Very pale yellow
Colour: Pale yellow to yellow-orange
Luminescence: Not fluorescent under UV
Environments
Sedimentary environments
Metamorphic evironments
Hydrothermal environments
Localities
At the type locality, E15-11 south stope, 11 level, Asis West sector, Kombat Mine, Kombat, Otavi Constituency, Otjozondjupa
Region, Namibia, the mineralisation consists of epigenetic (formed later than the enclosing rocks), hydrothermal, and
metasomatic replacement deposits, and fracture-filling
copper-lead-(silver)
sulphides, and a strong metamorphic overprint has given rise to lenses of
manganese-oxide, iron-oxide, and
iron-silicate minerals.
Carlfrancisite was found in 1982 associated with alleghanyite,
chlorite, pyrochroite,
spinel and ribbeite. Carlfrancisite and
associated manganese silicates and oxides occur as metamorphosed lenses associated with
copper-lead-silver
sulphide ores in feldspathic sandstone
that have subsequently been reworked by late hydrothermal solutions
(AM 98.1693-1696).
At the Garpenberg Norra mine, Garpenberg, Hedemora, Dalarna County, Sweden,
garpenbergite occurs with carlfrancisite and minor
stibarsen, paradocrasite and
filipstadite in a fractured
skarn matrix of granular
jacobsite, alleghanyite,
kutnohorite and dolomite
(MM 86.1.1–8).
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