Carminite

Formula: PbFe3+2(AsO4)2(OH)2
Anhydrous arsenate containing hydroxyl
Dimorph of mawbyite
Specific gravity: 4.10
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.

At the type locality, the Louise Mine, B├╝rdenbach, 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.

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