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