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Formula: PbFe3+2(AsO4)2(OH)2
Anhydrous arsenate containing hydroxyl
Paramorph of mawbyite
Crystal System: Orthorhombic
Specific gravity: 5.03 to 5.18 measured, 5.405 calculated
Hardness: 3½
Streak: Reddish-yellow
Colour: Carmine-red, terra cotta-red, reddish brown; red in transmitted light.
Solubility: Slowly soluble in hydrochloric acid with separation of PbCl2; completely soluble in nitric acid
Environments:
Carminite is a rare secondary mineral generally formed as an alteration
product of arsenopyrite in some oxidised lead-bearing
mineral deposits.
Common associates include beudantite,
scorodite,
dussertite, arsenopyrite,
bayldonite, mimetite,
cerussite,
anglesite, plumbojarosite
and wulfenite
(HOM, Mindat).
Localities
At the type locality, the Louise Mine, Bürdenbach, Germany, carminite is associated with
beudantite
Carminite has been found at the Ojuela mine, Mapimi, Durango, Mexico. The ores of the Ojuela Mine are
replacement deposits in
limestone and consist of
galena,
sphalerite, pyrite and
arsenopyrite in a matrix of
quartz,
dolomite and fluorite.
Arsenopyrite is abundant.
The oxidised ores are characterised by an abundance of arsenates, largely
mimetite,
together with wulfenite and the more ordinary oxide ore minerals. The
carminite
occurs in cavities in either scorodite or
arseniosiderite. It also forms heavy masses intimately mixed with
cerussite, anglesite and
plumbojarosite. It is almost always intimately associated with
arseniosiderite and
dussertite,
and it is the rarest of the arsenates in the association
(AM22.479-484).
Carminite from Ojuela - Image
At Hingston Down Consols Mine, Cornwall, England, UK, carminite occurs with
scorodite,
mimetite and
pharmacosiderite.
At the Tintic Mining District, Juab County, Utah, USA, several mines have yielded rare specimens of
carminite, which display deep red prismatic crystals to 0.5 mm in size, usually in radial aggregates on
quartz. It has been found at the Centennial Eureka, Mammoth, Gold Chain and
the lower dumps of the North Star mine. At the Centennial Eureka mine, carminite is associated with
arseniosiderite and
beudantite
(AM 55.2.187).
Carminite from the Tintic District -
Image
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