Anglesite

Yellow to white anglesite coating on metallic galena. Bear Hole Mine, Shullsburg, Lafayette County, Wisconsin. Sample is 6 x 5.5 x 5 cm. (Image courtesy of Tom Loomis, Dakota Matrix Minerals, Rapid City, South Dakota.)

Formula: PbSO4 Orthorhombic

Description:

Close-up of pale yellow anglesite crystals on galena. Largest crystal is about 2 mm across. Bear Hole Mine, Shullsburg, Lafayette County, Wisconsin. (Image courtesy of Tom Loomis, Dakota Matrix Minerals, Rapid City, South Dakota.)

Anglesite is a mineral that forms from the weathering of galena. It is often associated with other weathering of alteration minerals such as cerussite and smithsonite. It is usually a rather non-discript material, forming part of the drab white to gray to yellow rinds on galena. It is probably more wide-spread in the lead-zinc mining area in Iowa, Lafayette and Grant count than the listing indicates.

IOWA COUNTY: Irving (1883) describes small crystals of anglesite lining cavities in galena from near Mineral Point. Hobbs (1885) believes this and other reported occurrences in the Mineral Point area to be gypsum.

LAFAYETTE COUNTY: Klemic and West (1964) note anglesite is present as a rare secondary mineral formed from the weathering of galena in the many lead-zinc mines in the Belmont and Calamine Quadrangles.