This map shows a portion of New Guinea, but the plae occupied by Austrlai was left as open ocean.Copy of a map from 'A Short HIstory of Australia' by Ernest Scott.map, paris map, new guinea, early australian mapping

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

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. 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.A solid iron-magnesium silicate mineral with shades of green and brownburke museum, beechworth, geological, geological specimen, olivine, igneous rock, volcanic, gemstones, volcanic bomb, meteorites, asteroids, plantes, mount noorat, mount shadwell, indigenous, kirrae wuurong people, newer volcanics province, victoria, european settlement, eruption

Dendrites are deposits of black minerals, typically manganese oxides that precipitated from water seeping through fractures in fine-grain rocks like a sandstone or limestone. Dendrites are much less regular than plant fossils and lacks vein structures. The manganese cryztallizes through the process called 'supercooling'. Some samples of dendrites occur in volcanic rocks in the Lilydale district, east of Melbourne. Sandstones are made of tiny sand grains that may have been deposited in the sea and later formed together. Most sandstones are made of quartz which are chemically-resistant minerals. This particular specimen was donated by Alfred Selwyn in 1868 as part of the Geological Survey of Victoria. It is connected to the original 1875 catalogue on Geological Specimen with number 189 'Quartz Crystals_Quartz Crystals (two are polished)'Dendrites on sandstones This specimen is an important contribution to the geological history of Victoria, as well as its links to the 1868 Geological Survey of Victoria. This specimen is part of larger collection of significant geological specimens in the Burke Museum that was collected from around the world between 1868-1880. A large percentage of these specimens were collection as part of the Geological Survey of Victoria 1852-1974. The Geological Survey of Victoria was an organisation founded in response to the Victorian gold rush to explore the geological and mineral resources and to record a detailed map of the state. It was headed by British geologist, Alfred Richard Cecil Selwyn (1824-1902), who was responsible for issuing over 60 geological maps during his 17 years as director. These maps were all hand-drawn and coloured and became the benchmark for accuracy for geological mapping. 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 slice of light brown sandstone with dendrites formed from crystallized manganese oxide.Existing label: Not sure what / 'Slica dondrites' / means. / Sample is sandstone and original label / identifies it as from / the Grampians near Stawell. / C. Willman / 15/4/21 Other label: [illegible] / stone [ illegible] / from Grampians Stawell / 1894 /geological specimen, geology, geology collection, burke museum, beechworth, dendrites, sandstones, quartz, lilydale district, geological survey of victoria, grampians, victoria rocks, minerals, rocks, manganese oxides, alfred selwyn

Native Sulphur in its solid form is a yellow crystalline mineral that forms near volcanic vents and fumaroles where it is the solid form of hot gases. It is also frequently found in the subsurface as a by-product of sulphide ore mineralization. In all its forms, sulphur is one of the most commonly occurring minerals on the planet, especially in natural gases, and is key to the make-up of a range of other minerals. It is essential to continuing life on earth, and was used in ancient societies as part of medical care, religious rites, and entertainment, and was key to the invention of gunpowder by the Chinese. Native Sulphur in its solid form is a yellow crystalline mineral that forms near volcanic vents and fumaroles where it is the solid form of hot gases. It is also frequently found in the subsurface as a by-product of sulphide ore mineralization. In all its forms, sulphur is one of the most commonly occurring minerals on the planet, especially in natural gases, and is key to the make-up of a range of other minerals. It is essential to continuing life on earth and was used in ancient societies as part of medical care, religious rites, and entertainment, and was key to the invention of gunpowder by the Chinese. The exact site of extraction for this specimen is unknown, but it was probably collected in New Zealand in the 1850s. Sulphur is significant both for its historical and current uses, and for its nature as one of the most abundant minerals on the planet. Sulphur's importance comes both from its abundance and its role in ensuring survival, creating other minerals, and daily human life. This specimen is significant as representative of sulphur's solid properties. 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, small, crystalline mineral specimen that is largely bright yellow, with some darker spotting. geological specimen, geology, geology collection, burke museum, beechworth, sulphur, native sulphur, new zealand, native sulphur specimen, sulphur specimen

Thunderegg Agates are formed within rhyolite volcanic ash layers. They are rough spherical shapes, varying in size from less than an inch to over a metre long. Thundereggs usually contain centres of chalcedony which may have been fractured followed by deposition of agate, jasper or opal, either uniquely or in combination. A unique characteristic that these specimens have is the fact that they often look like ordinary rocks on the outside, but slicing them in half and polishing them may reveal intricate patterns and colours. These particular specimens are examples of thunderegg agates. Agate is a variety of chalcedony, a cryptocrystalline form of quartz. The agate component contributes to the intriguing internal patterns of the specimens. The specific locality of these specimens is unknown but they can be found in flows of rhyolite lava. They are formed in gas pockets in the lava, which act as moulds. These specimens can be found globally, with specific locations in Germany being particularly abundant. 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.Two small solid specimens with pale, sandy-coloured exteriors and fractured internal patterns. burke museum, beechworth, geological, geological specimen, thundereggs, thundereggs agate, agate, rhyolite, rhyolite lava, volcanic ash, chalcedony, cryptocrystalline

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

Galena is the natural compound of lead and classed as a sulphide, it crystallises in a cubic pattern and its chemical formula is PbS. Galena is a primary source of both lead and silver. This specimen of Galena comes from Broken Hill. Broken Hill has one of the world’s largest and most significant deposit of ore for the production of lead. Mining of Galena at Broken Hill began with the staking of land by Charles Rasp in 1883. By the following year, in 1884, Rasp and six others had formed Broken Hill Mining Company. Broken Hill Mining Company eventually evolved into BHP group limited and is currently the largest mining company in the world and the largest company in Australia. There is archaeological evidence from artefacts discovered in Turkey that humans have been extracting lead from galena by the process of smelting since at least 6500 BCE. This specimen also has quartz on the top surface which is frequently discovered alongside Galena. This mineral specimen is of historic significance as a sample of Galena extracted from Broken Hill during the 19th century. Mining for Galena in Broken Hill begin in 1883 by Charles Rasp and evolved into the world’s largest mining company – BHP Group Limited. Broken Hill is one of the world’s most significant deposits of ore for the production of lead. 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 flat, hand-sized, grey sulphide specimen that is the natural compound of lead with a quartz formation on the top surface. Existing Label: GALENA / (with quartz) / Locality: Broken Hill / N.S.W 120 x 70 x 29geological specimen, geology, geology collection, burke museum, beechworth, galena, galena quartz, quartz, charles rasp, broken hill mining company, bhp group limited, bhp, lead, ore, lead sulphide, sulphide, silver, broken hill

This specimen was recovered from Broken Hill, NSW. It was given the name Mangan Hedenbergite in 1819 by Jöns Jakob Berzelius in honor of Mr. Anders Ludvig of Hedenberg who was the first to define hedenbergite as a mineral. Hedenbergite, belongs in the pyroxene group having a monoclinic crystal system. The mineral is extremely rarely found as a pure substance. Mangan Hedenbergite is a manganese bearing variety of Hedenbergite. Manganese is the world’s fourth most used mineral after iron, aluminium, and copper primarily because it has no satisfactory substitute in its major applications. Globally, the steel industry is the primary user of manganese metal, utilizing it as an alloy to enhance the strength and workability of steel and in the manufacture of tin cans. Manganese is a key component of certain widely used aluminium alloys and, in oxide form, dry cell batteries used in electric vehicles. These batteries are in high demand. Another potential use for manganese may as an additive to help coat and protect a car’s engine. Manganese is also used for non-metallurgical purposes such as plant fertilizers, animal feed, and colorants for bricks. 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 mineral specimen in shades of silver and blackmanganese, open cut mine, manganese ore processing, bell bay, tasmania, northern territory, steel industry, zinc-carbon batteries, alkaline batteries, tin cans

The word Planisphere (Latin planisphaerium) was originally used in the second century by Claudius Ptolemy to describe the representation of a spherical Earth by a map drawn in the plane. This usage continued into the Renaissance: for example Gerardus Mercator described his 1569 world map as a Planisphere. The word describes the representation of the star-filled celestial sphere on the plane. The first star chart to have the name "Planisphere" was made in 1624 by Jacob Bartsch. Bartsch was the son-in-law of Johannes Kepler, discoverer of Kepler's laws of planetary motion. A significant item of celestial mapping used by marine navigators This particular item was made and used in the first quarter to half of the 20th centuryPlanisphere of northern hemisphere, with canvas bag. Planisphere consists of a circular star chart attached at its centre to an opaque circular overlay that has a clear elliptical window or hole so that only a portion of the sky map will be visible in the window or hole area at any given time. The chart and overlay are mounted so that they are free to rotate about a common pivot point at their centres. The star chart contains the brightest stars, constellations and (possibly) deep-sky objects visible from a particular latitude on Earth. The night sky that one sees from the Earth depends on whether the observer is in the northern or southern hemispheres and the latitude. A Planisphere window is designed for a particular latitude and will be accurate enough for a certain band either side of that. Planisphere makers will usually offer them in a number of versions for different latitudes. Planispheres only show the stars visible from the observer's latitude; stars below the horizon are not included. A complete twenty-four-hour time cycle is marked on the rim of the overlay. A full twelve months of calendar dates are marked on the rim of the starchart. The window is marked to show the direction of the eastern and western horizons. The disc and overlay are adjusted so that the observer's local time of day on the overlay corresponds to that day's date on the star chart disc. The portion of the star chart visible in the window then represents (with a distortion because it is a flat surface representing a spherical volume) the distribution of stars in the sky at that moment for the Planispheres designed location. Users hold the Planisphere above their head with the eastern and western horizons correctly aligned to match the chart to actual star positions. "Made in Germany for GEORGE PHILIP & SONS Ltd. Geographical and Educational Depot, 32 Fleet Street, London" Canvas bag has "Capt. H (Howard) Tyler from Captain H. F. Woolf" "Tyler 22 ? St East Brighton" also "13 Halls St Flinders"flagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village, planisphere, star map, marine navigation, maps, george philip & sons

The word Planisphere (Latin planisphaerium) was originally used in the second century by Claudius Ptolemy to describe the representation of a spherical Earth by a map drawn in the plane. This usage continued into the Renaissance: for example Gerardus Mercator described his 1569 world map as a Planisphere. The word describes the representation of the star-filled celestial sphere on the plane. The first star chart to have the name "Planisphere" was made in 1624 by Jacob Bartsch. Bartsch was the son-in-law of Johannes Kepler, discoverer of Kepler's laws of planetary motionA significant item of celestial mapping used by marine navigators This particular item was made and used in the first quarter to half of the 20th century.Planisphere consists of a circular star chart attached at its centre to an opaque circular overlay that has a clear elliptical window or hole so that only a portion of the sky map will be visible in the window or hole area at any given time. The chart and overlay are mounted so that they are free to rotate about a common pivot point at their centers. The star chart contains the brightest stars, constellations and (possibly) deep-sky objects visible from a particular latitude on Earth. The night sky that one sees from the Earth depends on whether the observer is in the northern or southern hemispheres and the latitude. A Planisphere window is designed for a particular latitude and will be accurate enough for a certain band either side of that. Planisphere makers will usually offer them in a number of versions for different latitudes. Planispheres only show the stars visible from the observer's latitude; stars below the horizon are not included. A complete twenty-four-hour time cycle is marked on the rim of the overlay. A full twelve months of calendar dates are marked on the rim of the star chart. The window is marked to show the direction of the eastern and western horizons. The disc and overlay are adjusted so that the observer's local time of day on the overlay corresponds to that day's date on the star chart disc. The portion of the star chart visible in the window then represents (with a distortion because it is a flat surface representing a spherical volume) the distribution of stars in the sky at that moment for the Planispheres designed location. Users hold the Planisphere above their head with the eastern and western horizons correctly aligned to match the chart to actual star positions. "Sold by J DONNE & SON, Booksellers & Stationers, 349 Post Office Place Melbourne 349. Admiralty Chart Agents" and " Made in Germany for George Philip & Son Ltd" England . Signature "Capt E. B. ?..id, 22 Baund St"flagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village, star map, marine navigation, maps, george philip & sons

Majority of Galena in Australia is found in hydrothermal deposits emplaced around 1680 million years ago which have been heavily metamorphosed. Galena is the natural mineral form of lead sulfaide. It occurs generally as fine to large crystals due to syntectonic remobilization at low temperatures and moves to a suitable location. The colour is a shining lead and silvery gray with high specific gravity between 7.2 and 7.6 gms/cm3 and contains 86.6 lead sulfaide in its purest form. Its cyrstal system is cubic with perfect cleavages, and contract penetration and lamellar twinning. This particular specimen is from the Broken Hill mine, it is one of the largest lead mines located in Western New South Wales and still has ore reserves amounting to 20.9 million tonnes of ore grading of 7.4% lead, 9.4% zinc, and 61.5 million oz of Silver. Throughout its history, it has produced over 200 million tonnes of ore throughout its 127 years of mining history dating back to 1885. Galena mineral ore found in Australia is considered rare, as it is only currently found in the Broken Hill Mine of Western New South Wales. It represents heritage value through the systematic collecting of the geological surveyers in Victoria and Australia during the early to late 19th Century. The fact that it is only found in one mining area of Australia, shows that this specimen is rare for examples of Australian Galena. This mineral specimen is one part to a larger collection, aquistion, and distribution of Garnet in Galena around Australia and parts of the world and donated to the Burke Museum between 1860-1880. While this specimen was not found by the Victorian Geological Survey, it shows the historical need for mapping geological areas around the Gold Rush region to further identify areas of precious metal and gem aquisition. Additionally, collecting these specimens was an important part of mapping the scientific make up of the earth's surface. Many were sent to institutions for further contribution to research and scientific knowledge of the specimens. A solid coin-sized lead and zinc sulphaide and zinc silicate ore mineral in shades of black and red with shiny black points. GARNET CRYSTALS in / GALENA (lead sulphide), / SPALERITE (zinc sulphide), / WILLEMITE (zinc silicate) ore. / Locality: Broken Hill, NSWburke museum, #beechworth, indigo shire, beechworth museum, geological, geological specimen, mineral, galena, galena quartz, broken hill mine, broken hill, nsw

Pyrite also known as iron Pyrite or fools gold is an iron sulfide with a chemical formula of FeS2 and is the most abundant sulfide mineral. Its metallic luster and pale brass-yellow hue give it a superficial resemblance to gold for which its nickname of Fools Gold comes from. There are a number of iron pyrite mines in Victoria and many would have been mined during Victoria's Gold Rush revolution in the 19th century. As it's lustrius yellow metallic look closely resembles gold, it is likely that it was often mistaken for gold as real gold was also often found in similar metamorphic and sedimentary rock. 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 collections were collected in Victoria as part of the Geological Survey of Victoria that begun in 1852 (in response to the Gold Rush). Collecting these specimens was an important part of Australia's early Geoplogical scientific discovery for mapping the earth's surface. It is unknown where in Victoria this specimen was mined from however; it shows strong provenance connections to Victoria's gold mining history and represents through larger economic and cultural structures the impact the Gold Rush had on Victoria during the 19th century. A solid coin-sized Pyrite crystal in black slate in shades of beige with tiny crystal structures. Pyrite / crystals / BB / in black slate / probably / victoria / (nice specimen)geology, geological specimen

Small rectangular arm, green map reading lamp with a slide-up black out adjustment. The lamp is battery operated and is fitted with webbing attachments.Diagram -three crowns. “12740-101010 JEA8”passchendaele barracks trust, mapping lamp, black out

Feldspar, derived from the German word feldspat, is a group of minerals which is the most common mineral group found on Earth, making up more than half of the planet's crust. The major rock-forming minerals in the Feldspar group include albite, anorthite, orthoclase and microcline. (Mindat, Feldspar Group). Orthoclase is part of the Feldspar Group subgroup, Alkaline Feldspar, which are known to be poor in calcium, and mostly rich in potassium. It is further also considered to be a K Feldspar, a subgroup of Alkaline Feldspar that are Potassium-dominant with variable crystal symmetry and Al-Si ordering state. Orthoclase are most commonly Colorless to white, Greenish white, Grayish yellow, or Pale pink and transparent to translucent with slightly pearly cleavage. The mineral rates at a 6 on the Mohs Hardness Scale. (cannot be scratched with a knife, but scratches glass with difficulty). The stronger green colour of this particular specimen is distinctive to the Broken Hill region (where it was found), and due to a small amount of lead. (BB) Its qualities find it misidentified at times as as microcline variety amazonite. Broken Hill is one of the world’s richest lead-zinc-silver deposits. The huge, 300-million-tonne orebody was discovered in 1883 and the superb mineral specimens attract collectors from around the world. (Australian Museum, Minerals from Australia: Australian mining regions)While feldspar is not by any means rare, this particular specimen has qualities distinctive to the Broken Hill mining district, with these properties leading at times to the mineral's misidentification. This creates potential for further study and identification of these mineral deposits through methods such as microscopic twinning, or using the position of certain d values in XRD patterns to calculate the degree of disorder of a K-feldspar, as discussed on the Mindat website (Mindat.com, Orthoclase:About Orthoclase). 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 small aluminosilicate mineral composition which is primarily pale green and blue-grey in colour with traces of beige and white throughout. Note: green plumbian orthoclase (aka green feldspar) is an indicator mineral for the Broken Hill style lead-zinc deposits.N/Abroken hill mine, geological specimen, minerology