Australasian Science: Australia's authority on science since 1938

Unique Mineral Described

A University of Adelaide researcher has discovered a new mineral that is unique in structure and composition among the world’s 4000 known mineral species. Dr Peter Elliott has described “putnisite” – found in a surface outcrop at Lake Cowan, north of Norseman in Western Australia – in Mineralogical Magazine.

“What defines a mineral is its chemistry and crystallography,” Elliott explains. “By X-raying a single crystal of mineral you are able to determine its crystal structure and this, in conjunction with chemical analysis, tells you everything you need to know about the mineral.

“Most minerals belong to a family or small group of related minerals, or if they aren’t related to other minerals they often are to a synthetic compound, but putnisite is completely unique and unrelated to anything.”

The new mineral, named after Australian mineralogists Andrew and Christine Putnis, occurs as tiny crystals no more than 0.5 mm in diameter. It appears as dark pink spots on dark green and white rock that, under the microscope, appears as square, cube-like crystals. It combines the elements strontium, calcium, chromium, sulfur, carbon, oxygen and hydrogen – a very unusual combination. It has yet to be determined if the new mineral will have any practical use.

The mineral was discovered during prospecting by a mining company in WA and handed to CSIRO for initial research and then to Elliott for more detailed analysis.