is a rare blue-green mineral
with the formula Cu++
O) (n<1) (making it a hydrated copper oxalate
). It was discovered by Richard M Clarke
and Ian R Williams
in Bunbury Well, Mooloo Downs station, Murchison
, Western Australia
. It has an orthorhombic
crystalline structure, and is formed by the interaction of bat guano
with weathering copper sulfides
A second occurrence is reported from the Sainte-Marie-aux-Mines silver mining district of Vosges Mountains, France.
Boyd-Graber, Jordan. A Field Guide to Australian Minerals.