Fluorite comes in a variety of natural colours and crystal formations and glows under ultraviolet light (the word 'fluorescence' comes from the same etymological source). In its pure form, calcium fluoride, it is a colourless combination of the elements calcium and fluorine, but gains its colour from trace elements that infiltrate or replace calcium within its crystal structure during its formation. Although fluorite crystals polish well and can achieve a high level of lustre, the mineral is very soft (4 on MOHS hardness scale) so it is unsuitable for use in rings and must be handled and stored carefully if used in other forms of jewellery. Most crystals of the mineral are too coarse for decorative purposes but have been mined under the name fluorspar for a variety of commercial and industrial purposes. These include the production of hydrofluoric acid, smelting metal alloys, producing glazes and ceramic finishes and use in medical and dental products. An existing label for this specimen indicates that its origin or collection-point was 'probably USA.' Fluorspar, the form of fluorite used commercially and industrially, was mined in significant quantities in the counties of Hardin and Pope in South-Eastern Illinois throughout the Nineteenth and Twentieth Centuries. Fluorite was made Illinois' state mineral in recognition of its contribution to the state's identity and economy. The specimens are significant as examples of surveying activity undertaken to assess and direct the development of the mineral resource industries, as well as the movement to expand human knowledge of earth sciences such as mineralogy and geology in the nineteenth century.The specimen is a piece of purple shaded fluorite (also known as fluorspar), the mineral form of calcium fluoride. The unpolished specimen presents a dark purple interior with a substantial dark grey crust representing the matrix from which the specimen was obtained. Existing label: Flourite / (purple) / probably / USA / BB /burke museum, beechworth, geological, geological specimen, fluorite, flourite, calcium fluoride, hydrofluoric acid, jewellery, indigo shire, north-east victoria, mining, illinois, usa, united states, fluorine, gemstones, purple stones

This specimen is from Broken Hill, NSW. Galena is a natural mineral form of lead sulphide and is often found associated with sphalerite, calcite, and fluorite. Galena is an important lead ore mineral, and, in some regions, it is also an important mineral associated with silver ore. Sphalerite is a sulphide mineral that is the main ore of zinc. Rhodonite is an uncommon mineral once used as an ore of manganese in India, however today the scarcity and fragility of the crystals mean it is primarily used as lapidary materials or mineral specimens. In 1883, Charles Rasp who was a boundary rider at the time, discovered what he thought were deposits of tin but were in fact samples of silver and lead. He and six others went on to set up the first mining company in Broken Hill (BHP). The ore body became the largest and richest of its kind in the world mining ore worth more than 42,000 pounds in its first year. Many of these specimens were sent to research and collecting organisations across Australia, including the Burke Museum, to educate and encourage further study. Galena contains lead and silver, Sphalerite contains zinc. 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 hand-sized piece of Sphalerite and Galena with Rhodonite crystalsburke museum, beechworth, geological, geological specimen, galena, rhodonite, sphalerite, silver ore, manganese, lead sulphide, lead ore, zinc ore, lapidary, mineral specimen, broken hill, nsw

Sphalerite or sphaelerite is named from the Greek word for 'treacherous' or 'deceiver' as specimens can vary widely in appearance, making them hard to visually identify. It is a zinc sulfide with the chemical composition (Zn,Fe)S, the most important ore of zinc. Specimens of sphalerite can contain iron as a substitute for up to 25% of the usual zinc present, as well as trace elements of gallium, cadmium, geranium and indium. Small amounts of arsenic and manganese may also be detected. Sphalerite is found in igneous, sedimentary and metamorphic rocks. It forms when carbonate rock encounters acidic, zinc-bearing fluid. It often forms in veins or in fissures of the existing rock, with colours and crystal shapes dependent on the composition of the the combining elements. It forms isometric crystal shapes including cubes, tetrahedrons, octahedrons, dodecahedrons. This specimen was collected in approximately 1852, in Broken Hill, NSW, as an adjunct to the Geological Survey of Victoria. It was donated to the Museum in 1868. Victoria and other regions of Australia were surveyed for sites of potential mineral wealth throughout the 19th Century. The identification of sites containing valuable commodities such as gold, iron ore and gemstones in a locality had the potential to shape the development and history of communities and industries in the area. The discovery of gold in Victoria, for instance, had a significant influence on the development of the area now known as 'the goldfields', including Beechworth; the city of Melbourne and Victoria as a whole.The specimen is significant as an examples of surveying activity undertaken to assess and direct the development of the mineral resource industries in Victoria and Australia, as well as the movement to expand human knowledge of earth sciences such as mineralogy and geology in the nineteenth century.A pipe-shaped specimen of sulfide-mineral zinc ore displaying patches of black, brown, beige and gold colouring. The main item has associated broken pieces. geological specimen, geology, geology collection, burke museum, beechworth, mineralogy, indigo shire, geological survey, sphalerite, sphaelerite, zinc ore, broken hill, nsw, victoria, galena, fluorite, chalcopyrite, lead, cadmium, gallium, germanium, indium, iron