Historical information

Olivine is mostly found on the Earth's surface in igneous rocks that are dark-coloured. It is common at divergent plate boundaries and at warm spots, such as volcanic areas. It crystalises and forms during the cooling of magma. Olivine is used in refractory sand, bricks, and gemstones.

Olivine has been found on a number of meteorites, which might have originated from large asteroids or the mantle of a now-destroyed planet.

This olivine crystal is thought to originate from Mount Noorat, with speculation that it could have originated from Mount Shadwell. Mount Noorat is a dormant volcano cone located in the Newer Volcanics Province of Victoria. Mount Noorat belongs to the Kirrae Wuurong people, who used the Mount as a place for meetings and gatherings prior to European settlement. Contact was first made between European settlers and the Indigenous people in 1841. The Mount has mostly been used for cattle and sheep grazing. Mount Shadwell is a well-known source of olivine and is the highest of a gathering of volcanic cones.

The New Volcanic Province is located in South East Australia and covers 15000 square kilometres. It contains 400 explosive vents and small shield volcanoes. The last eruption is thought to have occurred 5000 years ago at Mount Gambier and Mount Schank.

This olivine crystal has been identified as a volcanic bomb, which is a molten rock which was pushed out and ejected into the air when a volcano reupts. A rock needs to be larger than 65 mm in diameter to be classified as a volcanic bomb.

Significance

This olivine volcanic bomb and its locality is historically and socially significant. The olivine was found in the Newer Volcanic Province, an area which contains over 400 dormant volcanoes. This olivine is one part of a volcanic bomb, which would have ejected when magma erupted out of a volcano.

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 solid iron-magnesium silicate mineral with shades of green and brown

References