Carminite

carminite

dussertite

mawbyite

bayldonite

Images

Formula: PbFe3+2(AsO4)2(OH)2
Anhydrous arsenate
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:

Hydrothermal 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 Tsumeb, Oshikoto Region, Namibia, carminite forms acicular, translucent crystals and radial sprays and aggregates ranging in colour from reddish brown to deep red and reddish black. It was found rarely on Level 30, with beudantite and arseniosiderite comprising the most common suite, and with scorodite and anglesite forming a second suite, and very rarely with yellow-green gartrellite. Although the crystals rarely exceed 1 cm, Tsumeb carminite is still the finest in the world (Minrec 55.6.supplement p71).
Carminite from Tsumeb - Image

At Hingston Down Consols Mine, Cornwall, England, UK, carminite occurs with scorodite, mimetite and pharmacosiderite.

At Deer Hills, Caldbeck, Allerdale, Cumbria, England, UK, red splashes of carminite occur among brownish yellow beudanite.
Carminite from Deer Hills - Image

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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