Historical information

Selwynite is a fine-grained, compact green rock made primarily of chromian muscovite (fuchsite) and diaspore. Corundum and fuchsite can occur together in the form of massive aggregates or nodules. Often, copper carbonates are found as earthy films or tiny crystals in joint planes.

The mineral name honours the late A. R. C. Selwyn, founding Director of the Geological Survey of Victoria.

The particular specimen, a mottled green stone suitable for carving was recovered and found in Heathcote, Victoria, Australia. The rarity and qualities of this mineral attracted commercial mining, which was not successful, but traces of the mine shafts still exist today, and it is still highly valued by mineral collectors.

Significance

Selwynit is considered to be one of the rare forms of rock because it is composed of phosphate minerals containing zirconium. This is an extremely rare combination found in nature.

This specimen is part of a larger collection of geological and mineral specimens collected from around Australia (and some parts of the world) and donated to the Burke Museum between 1868-1880. A large percentage of these specimens were collected in Victoria as part of the Geological Survey of Victoria that begun in 1852 (in response to the Gold Rush) to study and map the geology of Victoria. Collecting geological specimens was an important part of mapping and understanding the scientific makeup of the earth. Many of these specimens were sent to research and collecting organisations across Australia, including the Burke Museum, to educate and encourage further study.

Physical description

A fine grained rock composed of mainly of chromian muscovite (fuchsite) diaspore and corundum.