There are 17 opal fields in Australia. This opal bearing stone was found in Lightning Ridge, NSW over what is known as the Great Australian Basin. This basin was formed and covers an area of 1.7 million square kilometers in eastern Australia in the Cretaceous period. This basin used to contain an inland sea, which provided an environment where silcrete eventually formed when water levels changed. This eventually seeped into other structures, and eventually hardened and formed opal.
Lightning Ridge has a population of around 2000 people, with about 80 000 visitors every year. It is a historic mining town, and is known for its deposits of a rare black opal. Mining started in the area in the late 1800s, early 1900s when the black opal was discovered.
This opal-bearing stone is of social and historical significance. It is from Lightning Ridge, which is well-known for being a large producer of opal stones, most famously black opal. The history of the period dates back to 140 million years, with the discovery of black opal in the early 1900s causing interest in the area.
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.
***A palm-sized solid mineral specimen in shades of beige and light orange*** silica based?