Historical information
Named in 1845 by Wilhelm Karl von Haidinger cerussite takes its name from the Latin cerussa, meaning 'white lead'. When viewed under certain lighting conditions cerussite gives of fire and rainbow-like colours (due to its high dispersion) and it is quite sought after by geological collectors for this very reason.
Cerussite is usually found in the oxidised zone of lead ore deposits. It is a very common weathering product of galena and other lead ore minerals. It is a secondary mineral, meaning it forms as a result of the alteration of pre-existing minerals in the Earth’s crust. The presence of lead in cerussite makes it potentially toxic. Historically, it has been an important source of lead, which has numerous industrial applications, including in batteries, construction materials, and radiation shielding. Cerussite has a crystal structure that belongs to the orthorhombic crystal system. Its crystal structure is characterized by a three-dimensional arrangement of atoms in a repeating pattern. The crystal lattice of cerussite consists of interconnected lead (Pb) and carbonate (CO3) ions. This crystal structure is visible in the specimen.
This specimen was found in Dundas (formerly Mount Dundas), a historical mining locality, mineral field and railway located on the western foothills of the West Coast Range in Western Tasmania. During the 1890s Dundas swelled in numbers however it is now lost in a temperate rainforest and its population is now 2. The present Dundas Extended mine, about 1.5 km east of Dundas is presently worked for specimen material.
Significance
Faceted cerussite gems are considered rare and valuable, given the softness of the mineral. This item is not a faceted gem however its historical and scientific research potential give it significance; mined in an Australian township, this cerussite could shed light on the now lost history of Dundas and the mining that occurred there. Additionally, the uses of this mineral in historical industrial processes give it scientific significance. Such knowledge can add to understandings of the geographical and geological nature of Western Tasmania and allow for further study of Australian geological specimens.
Physical description
A small lead carbonite mineral with shades of cream, white and brown throughout, flaky shards of white at base.
Inscriptions & markings
CERUSSITE / (lead carbonite) / Locality: Dundas, W. Tasmania
