dundasite (w. cerussite)

Bright blue sub-spherical, radial aggregates (to 6 mm) of bright, sky-blue dundasite, the colour intensity of which varies considerably but is undoubtedly due to copper; the colouring mechanism, however, has not been determined. Prismatic and blade-shaped cerussite crystals are associated as reticulated (twinned) aggregates. The cerussite is essentially colourless but with a matte white surface patina suggesting alteration to hydrocerussite (?) (Exhibit 2), although this has note been verified. A little azurite is present on the reverse of the specimen, and the matrix is a ferruginous intergrowth of calcite, cerussite and goethite.

The specimen was purchased from Rob Lavinsky in 2011. It was formerly in the collection of Marshall Sussman who acquired it with "an old African collection". The location in the mine is not recorded.

Dundasite has been verified by XRD (John Attard, Attard XRD Services; 2013).

azurite; calcite; cerussite; goethite; hydrocerussite (?)