Showing 188 items
matching mineral gold
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Federation University Historical Collection
Letter - Mining, Letter from William Plain, Secretary of Old Man's Hope Mineral and Gold Mining, 1898, 21/10/1898
... Mineral and Gold Mining, 1898...Old Man's Hope Mineral and Gold Mining... Mineral and Gold Mining...William Plain Old Man's Hope Mineral and Gold Mining ...Blue letter from William Plain, Secretary of Old Man's Hope Mineral and Gold Miningwilliam plain, old man's hope mineral and gold mining, lincoln changes collins street -
The Beechworth Burke Museum
Geological specimen - Chalcopyrite, Unknown
... mineral gold... golden appearance, it is often confused for the mineral gold... for the mineral gold, earning it the popular reputation as 'fool's gold ...This specimen was recovered from Mica Schist, Canada. Chalcopyrite is a copper iron sulfide mineral with a chemical composition of CuFeS2. Its name derives from the Greek words for copper (chalco-) and brass (pyrite). It can be found in shades of yellow, green and grey, and, when exposed to acid, it can change to purple, blue, violet and yellow tones. Weathering can cause loss of its metallic luster and its brass-yellow colour. Chalcopyrite forms under various conditions, with the most significant deposits being hydrothermal in their origin. It is known globally as the most important ore of copper for thousands of years, and is thus considered a very important mineral formation. Given its golden appearance, it is often confused for the mineral gold, earning it the popular reputation as 'fool's gold' or 'yellow copper'. However, it can be straightforwardly distinguished from gold; the latter is soft, with higher specific gravity and a yellow streak, whereas chalcopyrite is brittle, easily scratched by a nail, and has a greenish grey streak. Copper was the first metal that was used by people. It was discovered by the Neolithic man about 9,000 years ago and it gradually replaced stone as it was easier to be shaped. In Australia, search for copper began after the European settlement, leading to the discovery of substantial deposits, like the one at the Olympic Dam in South Australia, which is regarded as one of the largest copper deposits in the world. Chalcopyrite has been used for copper since smelting processes began approximately five thousand years ago. Although by no means rare, this the specimen of this mineral can be used to reflect a wider history of industrial uses of copper for a significant portion of human history. 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 solid hand-sized copper iron sulfide mineral of brass yellow, often with an iridescent tarnish, with greenish-black streak and submetallic luster. Chalcopyrite can be formed in several ways, including crystalizing from accessory minerals in igneous rocks, or from magma or within volcano sulfide deposits. Most commonly, chalcopyrite are found in hydrothermal conditions, where it forms in hydrothermal veins. As a member of the tetragonal crystal system, it often takes the shape of tetra-headed crystals, often with striations along the sides of the crystals. #18 Copper pyrites/(chalcopyrite) in/Laurentian Slate/(page 315 of inventory)/page missing from/descriptive catalogue/ Other label: 81 /fool's gold, chalcopyrite, mineral, rock, geology, geological, hydrothermal, neolithic, european settlement, olympic dam, south australia, stone, deposits, specific gravity, greenish grey streak, brittle, mineral gold, metallic luster, cufes2, greek words -
Bendigo Historical Society Inc.
Book - AUSTRALIAN MINING HISTORY MONOGRAPHS, NUMBER 7, THE ROLE OF MINERALS SEPARATION LTD. IN THE DEVELOPMENT OF THE FLOTATION PROCESS, c2000
... Goldfields gold mineral separation Mining history Australia minerals ...Australian Mining History Monographs Number 7, The Role of Minerals Separation in the Development of the Flotation Process. Paper presented at the Australian Mining History Association meeting, Adelaide 5 July 2000. Publisher: Zlota, Strathfieldsaye, Victoria. 45 pages.Ralph W Birrellgold, goldfields, gold, mineral separation, mining history, australia, minerals separation, flotation process -
The Beechworth Burke Museum
Geological specimen - Gold Telluride Ore
... minerals with tellurium, sulphur, or selenium. The gold-bearing...A hand-sized silvery to pyrite-yellow striated mineral... minerals with tellurium, sulphur, or selenium. The gold-bearing ...Gold usually is found as a native metal, but it also forms minerals with tellurium, sulphur, or selenium. The gold-bearing minerals that contain tellurium are called tellurides. Kalgoorlie, Western Australia contains greater than 1500 tonnes of gold.Seventy to seventy-five percent of the deposit occurs as native gold, but a further twenty percent appears as tellurides. What remains is in the form of 'invisible' gold. Extracting gold from telluride minerals, such as calaverite, which contains around forty-two percent gold, has produced approximately three hundred tonnes of gold. Prior to 1896, rocks containing tellurides were not recognised as rich gold ores, and were discarded.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 silvery to pyrite-yellow striated mineral containing tellurium and goldburke museum, beechworth, beechworth museum, geological, geological specimen, mineralogy, telluride, tellurite, gold-bearing, kalgoorlie, tellurium -
Federation University Historical Collection
Photograph - coloured, Department of Lands and Survey, Portion of Victoria showing auriferous areas and mineral localities, 1935
... Map included with book "Victoria: Gold and Minerals" issued... and mineral localities, 1935 Fold out coloured map Yellow mark ...Map included with book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Fold out coloured mapYellow mark indicating depositsvictoria, auriferous areas, mineral localities, department of mines, tin, antimony, copper, silver lead, tungsten, manganese, platinum, iron -
Federation University Historical Collection
Photograph - black and white, Mines Department Geological Museum and Library, Melbourne
... Photograph included in book "Victoria: Gold and Minerals... "Victoria: Gold and Minerals" issued by Mines Department Victoria ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, mines department, melbourne, geological museum, geological library -
Federation University Historical Collection
Photograph - black and white, State Electricity Commission, Excavating Brown Coal at open-cut, Yallourn
... Photograph included in book "Victoria: Gold and Minerals..., Yallourn Photograph Photograph included in book "Victoria: Gold ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, excavating, dredge, brown coal, yallourn -
Federation University Historical Collection
Photograph - black and white, State Coal Mine at Wonthaggi showing the Conveyor System
... Photograph included in book "Victoria: Gold and Minerals...: Gold and Minerals" issued by Mines Department Victoria, 1935 ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, brown coal, wonthaggi, coal mine, conveyor system, mining -
Federation University Historical Collection
Photograph - black and white, Puddling Machine used in Gold Mining
... Photograph included in book "Victoria: Gold and Minerals... Photograph Photograph included in book "Victoria: Gold and Minerals ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, puddling machine, horse, gold mining, mining -
Federation University Historical Collection
Photograph - black and white, Whim: an appliance used for Shaft Haulage
... Photograph included in book "Victoria: Gold and Minerals... Haulage Photograph Photograph included in book "Victoria: Gold ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, horse, gold mining, whim, shaft haulage, mining -
Federation University Historical Collection
Photograph - black and white, Prospecting Methods - Hand Dollying
... Photograph included in book "Victoria: Gold and Minerals... Photograph Photograph included in book "Victoria: Gold and Minerals ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, gold mining, hand dollying, prospecting method, prospecting, mining, tools -
Federation University Historical Collection
Photograph - black and white, Panning Off
... Photograph included in book "Victoria: Gold and Minerals... and Minerals" issued by Mines Department Victoria, 1935 victoria gold ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Image of two men involved in panning for gold. victoria, gold mining, prospecting method, creek bed, panning, gold panning, gold pan, mining, prospecting, tools -
Federation University Historical Collection
Photograph - black and white, Hydraulic sluicing
... Photograph included in book "Victoria: Gold and Minerals...: Gold and Minerals" issued by Mines Department Victoria, 1935 ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photograph of a hydraulic sluice in action. victoria, gold mining, prospecting method, sluicing, hydraulic, hydraulic sluice, mining -
Federation University Historical Collection
Photograph - Photograph - black and white, Talbot Alluvial Mine: working a deep lead
... Photograph included in book "Victoria: Gold and Minerals...: Gold and Minerals" issued by Mines Department Victoria, 1935 ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, prospecting method, talbot, alluvial mine, gold mining, mining, poppet head -
Federation University Historical Collection
Photograph - black and white, Mines Department Laboratory, Melbourne
... Photograph included in book "Victoria: Gold and Minerals... Photograph Photograph included in book "Victoria: Gold and Minerals ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, melbourne, mines department, laboratory -
Federation University Historical Collection
Photograph - black and white, Mt Buffalo: a granitic massif intruded into silurian strata: Ovens Valley in background
... Photograph included in book "Victoria: Gold and Minerals... included in book "Victoria: Gold and Minerals" issued by Mines ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, mt buffalo, ovens valley -
Federation University Historical Collection
Photograph - black and white, Jamieson Valley: Broad alluvial flats of recent geological formation: Silurian and Devonian Ranges in background
... Photograph included in book "Victoria: Gold and Minerals... in background. Photograph Photograph included in book "Victoria: Gold ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, jamieson valley, geological formation, alluvial flats, silurian, devonian -
Federation University Historical Collection
Photograph - black and white, Miners at work underground with a pneumatic drill
... Photograph included in book "Victoria: Gold and Minerals...: Gold and Minerals" issued by Mines Department Victoria, 1935 ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, underground drilling, pneumatic drill, rail tracks, hand pushed cart, gold mining, mining, tools -
Federation University Historical Collection
Photograph - black and white, New Red, White and Blue Consolidated Mine, Bendigo
... Photograph included in book "Victoria: Gold and Minerals...: Gold and Minerals" issued by Mines Department Victoria, 1935 ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, bendigo, consolidated mine, tower, new red, white and blue consolidated mine, poppet head, mining, gold mining -
Federation University Historical Collection
Photograph - colour, William Baragwanath, Department of Mines: Geological map of Victoria, c1935
... Photograph included in book "Victoria: Gold and Minerals... Photograph Photograph included in book "Victoria: Gold and Minerals ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographmap, department of mines, victoria, key to land formations, time periods, jurassic, geological map -
Federation University Historical Collection
Photograph, State Electricity Commission, Electric Power Station and Brown Coal Briquetting Factory at Yallourn
... Photograph included in book "Victoria: Gold and Minerals... "Victoria: Gold and Minerals" issued by Mines Department Victoria ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Photographvictoria, brown coal, briquettes, electric, power station, electricity, yallourn, mining -
Federation University Historical Collection
Photograph - Photograph - black and white, Sluicing in a creek bed
... Photograph included in book "Victoria: Gold and Minerals... included in book "Victoria: Gold and Minerals" issued by Mines ...Photograph included in book "Victoria: Gold and Minerals" issued by Mines Department Victoria, 1935Image of a man sluicing in a creek bed. victoria, gold mining, prospecting method, sluicing, creek bed, mining, tools, prospecting -
Clunes Museum
document
... . THE GOLDFIELDS AND MINERAL DISTRICTS OF VICTORIA. GOLD ITS OCCURRENCE... & STAMPS (Extract taken from publication, The Gold Fields, Mineral... & STAMPS (Extract taken from publication, The Gold Fields, Mineral ...INFORMATION ABOUT A STAMP SHOE FROM A CORNISH STYLE SQUARE-HEAD STAMP BATTERY POSSIBLY USED BY PORT PHILLIP MINE, CLUNES, FROM MATTHEW CHURCHWARD, SENIOR CURATOR, ENGINEERING & TRANSPORT, MUSEUM OF VICTORIA LETTER DATED 15 OCTOBER, 1997. THE GOLDFIELDS AND MINERAL DISTRICTS OF VICTORIA. GOLD ITS OCCURRENCE AND EXTRACTION, PLAN OF GOLD MINING COMPANIESINFORMATION RECEIVED REGARDING THE PORT PHILLIP MINE; Including .1 COPY OF ARTICLE 12TH MAY, 1858 FROM "THE ARGUS." MELBOURNE. .2 LETTER FROM "SCIENCEWORKS" TO MR. ALAN KEEBLE DATED 15/10/1997 (3 Pages) .3 SECTION OF MERCURY, TROUGHS, STAKES & STAMPS (Extract taken from publication, The Gold Fields, Mineral Districts of Victoria, by R. Brough Smyth F.G.S, published by Queensberry Hill Press 1979) .4 GOLD. ITS OCCURRENCE AND EXTRACTION (Extract taken from publication, Gold: Its Occurrence and Extraction by Alfred G. Lock F.R.G.S published by E. & F. N. Spon 16 Charing Cross London 1882) .5 PLAN OF GOLD MINING CO'S. CLUNES (Extract taken from Dicker's Mining Record 26/3/1867, page 173. https://trove.nla.gov.au/work/32734386?q&versionId=39944948) local history, mining, company exploration -
Bendigo Historical Society Inc.
Book - BOOK - VICTORIA: GOLD AND . . MINERALS
... A copy of the 1935 guide book Victoria: GOLD and MINERALS... - VICTORIA: GOLD AND . . MINERALS ...A copy of the 1935 guide book Victoria: GOLD and MINERALS . This book gives in great detail about promising mining areas in Victoria along with detailed maps of them.book, bendigo, mining -
Federation University Historical Collection
Book, Prospecting, Locating and Valuing Mines, 1902
... Development of Mines; Earthy Mineral Products; Coal; Gold gravels... Prospecting, Locating and Valuing Mines Black covered book with gold ...This book was most probably used at the Ballarat School of Mines.Black covered book with gold title. 381 pages. The book was 'a popular treatise for the use of prospectors, investors and Mining Men generally; with an account of the Principal Minerals and Country rocks; Ore Deposits; Locations and Patents; the early Development of Mines; Earthy Mineral Products; Coal; Gold gravels and gravel Mining; Measurement of Water; and Artesian Wells'.mining, ballarat school of mines, water, geology -
City of Moorabbin Historical Society (Operating the Box Cottage Museum)
Functional object - Gold Mining, prospector's "rocker", c1870
... would then use his gold pan to sort out the heavy minerals..., the miner would then use his gold pan to sort out the heavy minerals ...Gold was discovered in Victoria c1850 and people came from all over the world to seek their fortune at Ballarat and Bendigo and surrounding gold fields. This large wooden rocking- box or cradle was used by gold prospectors. A handle on the rocker is pushed back and forth, as the miner put gravel into the top part and finer and heavier particles dropped through a screen, helped along by buckets of water. The bottom part of the device had slats, that caught the heavier metals. After many shovel loads of gravel were pushed through the rocker, the miner would then use his gold pan to sort out the heavy minerals to find gold. Most of the pioneer settlers in Moorabbin Shire left the area to try their luck at gold mining and there was a desperate shortage of workers to maintain the market gardens and supply food to the ever increasing population of Melbourne.This gold prospector's 'cradle' is hand made and typical of those used by many hopeful Moorabbin Shire pioneers as they abandoned their market gardens to try their luck at finding gold in the Ballarat and Bendigo minefields c1850This gold miner's rocker is very old, and very well-used. It is a large wooden rocking- box or cradle used by gold prospectors. A handle on the rocker is pushed back and forth, as gravel is put in the top part of the box so that finer and heavier particles drop through a screen.. The bottom part of the device had slats, that caught the heavier metals. i.e gold particles. The water passed through the shute at the base back into the creek or river.moorabbin, brighton, market gardens, pioneers, early settlers, fruit, vegetable, ballarat, bendigo, gold mining, gold prospedtors, gold rush, were j. b., irish immigrants, chinese immigrants, gold panning, gold digger -
The Beechworth Burke Museum
Geological specimen - Unknown, possible Carnelian Agate or Chalcedony
Although it is not known where these specimens were collected, 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. Agate occurs when amygdales (gas pockets) form in the upper levels of basaltic lava flows. If these pockets or bubbles are iniltrated by water bearing silica in solution, the fluid dries and hardens in layers, forming round or egg shaped nodules or geodes within the rocky matrix. Agate is formed of a silica mineral chalcedony similar to quartz. The term carnelian primarily refers to the reddish shading of the stone; whether the stone is termed an agate or chalcedony type is often influenced by the degree of colour banding the specimen shows. The specimens are significant as 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.Three small geological specimens that appear visually consistent with images of rough or unpolished Carnelian Agate or Chalcedony. geological specimen, geology, geology collection, burke museum, beechworth, indigo shire, north-east victoria, gemstones, agate, carnelian -
The Beechworth Burke Museum
Geological specimen - Smoky quartz crystals, unknown
Quartz is an extremely common mineral to find across the world. Quartz can have two forms; Microcrystalline quartz or Crystalline quartz. Microcrystalline quartz is a fine grain quartz where crystalline quartz is often a large crystal. This specimen is a crystalline quartz. Made of silicon oxide, this specimen is called smokey quartz crystals because of its brownish colour. However, the colour of quartz can vary. In addition, quartz are formed in deep-seated igneous rocks and crystallized through hot aqueous solutions. This type of crystal can be found all over Australia, including Beechworth in Victoria. Other places quartz can be found is the Ashburton River area in Western Australia, Marlborough in Queensland, the Lune River area in Tasmania and Kingsgate in New South Wales. This specimen is significant because it is common to find this kind of mineral. While the location of where this specimen was originally from is unknown, it highlights the many places in Australia where quartz is found. It demonstrates that quartz makes up a large portion of Australia's geology. In addition, quartz itself can vary in its colour and shape. This specimen represents one of these variations. That being smoky quartz crystals. 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 large hand-sized quartz mineral with shades of brown and gray throughout.Smoky quartz / crystals /locality/ unknown / (needs a wash) /BBgeological specimen, geology, geology collection, burke museum, beechworth, microcrystalline, quartz, quartz mining, quartz reefs beechworth, smokey quartz crystals, crystals, crystalline, silicon oxide, brown, colour, igneous rocks, magma, ashburton river, western australia, marlborough, queensland, lune river, tasmania, kingsgate, new south wales, nsw -
The Beechworth Burke Museum
Geological specimen - Fossil Leaves
A fossil refers to any remains or traces of past life that are preserved in the rock. It could be remains of plants or animals. Fossil leaves are commonly found on different types of rocks. These fossils can go as far back as the Triassic Age just like the series of fossil plants collected at Denmark Hill, Ipswich in Queensland. Fossils leaves are formed when dead plants get buried by sediments like mud, sand, or volcanic ash. Often, it gets detached cleanly from stems along a special layer of weak cells, then twigs, and, less commonly, cones of conifers and fruits and seeds of flowering plants. Over time, the leaves or pieces of leaves get buried by more sediments and eventually gets 'lithified' or hardened into a rock. Erosions and mining can cause the rocks to break and reveal the fossils buried in it. Fossilisation frequently takes place at sites in the lowlands where deposits of clay, silt, sand are found. This is usually due to weathering and erosion of rocks. Fossil leaves can provide information about ancient Australia's way of living. It contributes to Victorian biodiversity records and its botanical collections. It also contributes information on the geographical profile of Victoria as fossilisation usually occur at estuaries and deltas of rivers, river flood plains, ponds and lakes. 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.Piece of light brown rock with fossilised leaves in shades of golden yellow and brown.Existing label: Fossil Leaves / Locality unknown / might be worth checking if this is Glossopteris, a Permian age plant. / C. William 16/4/21 geological specimen, geology, geology collection, burke museum, beechworth, fossil leaves, fossilization, 1868 geological survey of victoria, lithified, rocks, fossilised leaf, rock, fossils, leaves -
The Beechworth Burke Museum
Geological specimen - Common Opal, unknown
Common Opal is a mineraloid that is non crystallising and is classed as an amorphous silicate, the chemical composition for Opal is SiO2 nH2O. Opals can develop in weathered sedimentary rock typical in arid regions where limited water enters small gaps in the rock, and the silicate is hydrated. Common opals, unlike precious opals, do not exhibit ‘play of colour’ in which the colour appears to change depending on the angle of view. While precious opals are highly valuable and cut as gemstones for jewellery, common opals can be cut into inexpensive gemstones and are also mined for various uses including as ingredients in ceramics, insulation, fillers, and abrasives. The source of this common opal specimen is unknown, but common opals are found around the world, notable deposits are found in Queensland, South Australia, New South Wales, Peru, Kenya, Nevada, Oregon, and Mexico. This common opal specimen is of historic and scientific significance due to its donation in 1868 as part of the Geological Survey of Victoria and as a typical example of uncut common opal. 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 amorphous (non-crystallising) hydrated silicate mineraloid specimen in shades of brown, orange, and white.Existing label: Common Opal / Locality unknowngeological specimen, geology, geology collection, burke museum, beechworth, common opal, opal, mineraloid, amorphous silicates, hydrated silicate