Wulfenite (w. azurite)

azurite; calcite; dundasite (?); malachite; quartz; tsumcorite (?)

azurite; calcite; dundasite (?); malachite; quartz; tsumcorite (?)

A vug in oxidising sulphide ore hosts free-standing colourless quartz crystals overgrown by rhombs of white calcite and tabular pale tan wulfenite crystals (to 3 mm on edge). Crystals of bright blue azurite (to 6 mm) have partly overgrown the wulfenite; the azurite is heavily etched giving the surface a velvety appearance but greatly enhancing the blue colour. One or two azurite crystals have altered to malachite, but malachite also occurs as spherules and micro-botryoidal crusts that are not pseudomorphous; it appears to be the last-formed mineral in this paragenesis.

A separate vug on the reverse of the specimen (Exhibit 2) hosts quartz crystals partly coated with a yellow-orange mineral provisionally identified as tsumcorite (?). Feathery radial sprays (to 1.5 mm) of white dundasite (?) needles and spherules of malachite (< 0.2 mm) rest on the tsumcorite (?).

Mark Feinglos purchased this mineral from British dealer Richard Barstow. The location in the mine is not recorded.