Duftite

arsenate

descloizite

Formula: PbCu(AsO4)(OH)
Anhydrous arsenate containing hydroxyl, adelite - descloizite group, forms series with conichalcite and with mottramite.
Specific gravity: 6.12
Hardness: 4½
Streak: Pale green, white
Colour: Olive-green, grey-green; light apple-green in transmitted light.
Environments:

Hydrothermal environments

Duftite is a secondary mineral that occurs in the oxidised zone of hydrothermal metal ore deposits. At the type locality it is associated with azurite (Mindat).

Localities

At Arm O'Grain, Cumbria, England, mottramite and duftite are almost indistinguishable, due to much arsenate substitution for vanadate in mottramite. It occurs with mimetite (JRS 9.48).

At Driggith and Sandbed Mines, Cumbria, England, duftite is associated with mottramite (JRS 9.20).

At Short Grain, Cumbria, England, duftite occurs rarely in vugs in quartz and baryte, commonly overgrown by mimetite (JRS 12.53).

At the San Rafael Mine, Nevada, USA, duftite occurs in pods of limonite associated with adamite, segnitite, wulfenite and mimetite (R&M 88.6.517-518).

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