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Childrenite
Childrenite is a rare hydrated phosphate mineral with elements iron, manganese, aluminium, phosphorus, oxygen and hydrogen. Its chemical formula is and it has a molecular weight of 229.83 g/mol. Its specific gravity is 3.2 and it has a Mohs hardness of 4.5 to 5. It is usually translucent and non-fluorescent, with imperfect cleavage. It has a vitreous lustre with a white streak, and is brown or yellow in color. It has a conchoidal, uneven fracture, and an orthorhombic crystal system. History and formation Childrenite was discovered in 1823 by John George Children (1777–1852), who was a prominent English chemist and mineralogist. This secondary mineral was first found in the George and Charlotte Mine near Tavistock in Devon. Its formation is probably from the alteration of granitic phosphates like lithiophilite and triphylite. Childrenite is also found in some ore veins. Relationship to other species Childrenite forms a solid solution series with eosphorite. The chem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John George Children
John George Children FRS FRSE FLS PRES (18 May 1777 – 1 January 1852 in Halstead, Kent) was a British chemist, mineralogist and zoologist. He invented a method to extract silver from ore without the need for mercury. He was a friend of Sir Humphry Davy, who helped him secure a controversial appointment to a post in the British Museum. Children was also the founding president of the Royal Entomological Society. Personal life John George was born on 18 May 1777 at Ferox Hall, Tonbridge, Kent. His father George Children, FRS (1742–1818), a banker, belonged to a family that lived at the home, "Childrens", near Nether Street in Hildenborough and his mother Susanna, who was the daughter of Rev. Thomas Marshall Jordan of West Farleigh died six days after he was born. Children studied at Tonbridge School, Eton College and Queens' College, Cambridge. In 1798 he married Hester Anna Holwell, granddaughter of John Zephaniah Holwell in 1798. After her death in 1800, he began to travel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate Minerals
Phosphate minerals contain the tetrahedrally coordinated phosphate (PO43−) anion along sometimes with arsenate (AsO43−) and vanadate (VO43−) substitutions, and chloride (Cl−), fluoride (F−), and hydroxide (OH−) anions that also fit into the crystal structure. The phosphate class of minerals is a large and diverse group, however, only a few species are relatively common. Applications Phosphate rock has high concentration of phosphate minerals, most commonly of the apatite group. It is the major resource mined to produce phosphate fertilizers for the agriculture sector. Phosphate is also used in animal feed supplements, food preservatives, anti-corrosion agents, cosmetics, fungicides, ceramics, water treatment and metallurgy. The largest use of minerals mined for their phosphate content is the production of fertilizer. Phosphate minerals are often used for control of rust and prevention of corrosion on ferrous materials applied with electrochemical conversion co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescent
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, than the absorbed radiation. A perceptible example of fluorescence occurs when the absorbed radiation is in the ultraviolet region of the electromagnetic spectrum (invisible to the human eye), while the emitted light is in the visible region; this gives the fluorescent substance a distinct color that can only be seen when the substance has been exposed to UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after. Fluorescence has many practical applications, including mineralogy, gemology, medicine, chemical sensors (fluorescence spectroscopy), fluorescent labelling, dyes, biological detectors, cosmic-ray detection, vacuu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devon
Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is a coastal county with cliffs and sandy beaches. Home to the largest open space in southern England, Dartmoor (), the county is predominately rural and has a relatively low population density for an English county. The county is bordered by Somerset to the north east, Dorset to the east, and Cornwall to the west. The county is split into the non-metropolitan districts of East Devon, Mid Devon, North Devon, South Hams, Teignbridge, Torridge, West Devon, Exeter, and the unitary authority areas of Plymouth, and Torbay. Combined as a ceremonial county, Devon's area is and its population is about 1.2 million. Devon derives its name from Dumnonia (the shift from ''m'' to ''v'' is a typical Celtic consonant shift). During the Briti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tavistock, Devon
Tavistock ( ) is an ancient stannary and market town within West Devon, England. It is situated on the River Tavy from which its name derives. At the 2011 census the three electoral wards (North, South and South West) had a population of 13,028. It traces its recorded history back to at least 961 when Tavistock Abbey, whose ruins lie in the centre of the town, was founded. Its most famous son is Sir Francis Drake. History Middle Ages The area around Tavistock (formerly Tavistoke), where the River Tavy runs wide and shallow allowing it to be easily crossed, and near the secure high ground of Dartmoor, was inhabited long before historical records. The surrounding area is littered with archaeological remains from the Bronze and Iron Ages and it is believed a hamlet existed on the site of the present town long before the town's official history began, with the founding of the Abbey. The abbey of Saint Mary and Saint Rumon was founded in 961 by Ordgar, Earl of Devon. After destruct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic viability of investing in the equipment, labor, and energy required to extract, refine and transport the materials found at the mine to manufacturers who can use the material. Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineralogist
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization. History Early writing on mineralogy, especially on gemstones, comes from ancient Babylonia, the ancient Greco-Roman world, ancient and medieval China, and Sanskrit texts from ancient India and the ancient Islamic world. Books on the subject included the ''Naturalis Historia'' of Pliny the Elder, which not only described many different minerals but also explained many of their properties, and Kitab al Jawahir (Book of Precious Stones) by Persian scientist Al-Biruni. The German Renaissance specialist Georgius Agricola wrote works such as '' De re metallica'' (''On Metals'', 1556) and ''De Natura Fossilium'' (''O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemist
A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms. Chemists carefully measure substance proportions, chemical reaction rates, and other chemical properties. In Commonwealth English, pharmacists are often called chemists. Chemists use their knowledge to learn the composition and properties of unfamiliar substances, as well as to reproduce and synthesize large quantities of useful naturally occurring substances and create new artificial substances and useful processes. Chemists may specialize in any number of subdisciplines of chemistry. Materials scientists and metallurgists share much of the same education and skills with chemists. The work of chemists is often related to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, and includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Paleolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century and has had a significant cultural and legal impact on the wider world since the Age of Discovery, which began during the 15th century. The English language, the Anglican Church, and Engli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthorhombic
In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base (''a'' by ''b'') and height (''c''), such that ''a'', ''b'', and ''c'' are distinct. All three bases intersect at 90° angles, so the three lattice vectors remain mutually orthogonal. Bravais lattices There are four orthorhombic Bravais lattices: primitive orthorhombic, base-centered orthorhombic, body-centered orthorhombic, and face-centered orthorhombic. For the base-centered orthorhombic lattice, the primitive cell has the shape of a right rhombic prism;See , row oC, column Primitive, where the cell parameters are given as a1 = a2, α = β = 90° it can be constructed because the two-dimensional centered rectangular base layer can also be described with primitive rhombic axes. Note that the length a of the primit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture
Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displacement develops perpendicular to the surface, it is called a normal tensile crack or simply a crack; if a displacement develops tangentially, it is called a shear crack, slip band or dislocation. Brittle fractures occur with no apparent deformation before fracture. Ductile fractures occur after visible deformation. Fracture strength, or breaking strength, is the stress when a specimen fails or fractures. The detailed understanding of how a fracture occurs and develops in materials is the object of fracture mechanics. Strength Fracture strength, also known as breaking strength, is the stress at which a specimen fails via fracture. This is usually determined for a given specimen by a tensile test, which charts the stress–strain cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conchoidal
Conchoidal fracture describes the way that brittle materials break or fracture when they do not follow any natural planes of separation. Mindat.org defines conchoidal fracture as follows: "a fracture with smooth, curved surfaces, typically slightly concave, showing concentric undulations resembling the lines of growth of a shell".Conchoidal fracture at Mindat.org Materials that break in this way include , , |
