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Mineraloids
A mineraloid is a naturally occurring substance that resembles a mineral, but does not demonstrate the crystallinity of a mineral. Mineraloid substances possess chemical compositions that vary beyond the generally accepted ranges for specific minerals, for example, obsidian is an amorphous glass and not a true crystal; lignite ( jet) is derived from the decay of wood under extreme pressure underground; and opal is a mineraloid substance because of its non-crystalline nature. Pearl is a mineraloid substance because the calcite crystals and the aragonite crystals are bonded by an organic material, and naturally occurs without definite proportions of the components. The first usage of the term ''mineraloid'' substance was in 1909, by mineralogist and geologist Julian Niedzwiedzki, in identifying and describing amorphous substances that resemble minerals. Examples * Allophane, solid (IMA/CNMNC valid mineral name) * Amber, non-crystalline structure, organic * Anthracite or hard coal * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Minerals'; p. 1. In the series ''Geology: Landforms, Minerals, and Rocks''. Rosen Publishing Group. The Geology, geological definition of mineral normally excludes compounds that occur only in living organisms. However, some minerals are often biogenic (such as calcite) or organic compounds in the sense of chemistry (such as mellite). Moreover, living organisms often synthesize inorganic minerals (such as hydroxylapatite) that also occur in rocks. The concept of mineral is distinct from rock (geology), rock, which is any bulk solid geologic material that is relatively homogeneous at a large enough scale. A rock may consist of one type of mineral or may be an aggregate (geology), aggregate of two or more different types of minerals, spaci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Mineralogist
''American Mineralogist: An International Journal of Earth and Planetary Materials'' is a peer-reviewed scientific journal covering the general fields of mineralogy, crystallography, geochemistry, and petrology. It is an official journal of the Mineralogical Society of America, publishing both subscription and open access articles. The journal is a hybrid open-access journal. The editors-in-chief are Hongwu Xu (Los Alamos National Laboratory), and Don Baker (McGill University). History The journal was established in 1916, with the first issue appearing in July of that year, under the auspices of the ''Philadelphia Mineralogical Society'', the ''New York Mineralogical Club'', and the ''Mineral Collectors' Association''. On December 30, 1919, the Mineralogical Society of America was formed and ''American Mineralogist'' became the society's journal. Abstracting and indexing The ''American Mineralogist'' is abstracted and indexed in Chemical Abstracts, the Science Citation Index, Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignite
Lignite (derived from Latin ''lignum'' meaning 'wood'), often referred to as brown coal, is a soft, brown, combustible sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35% and is considered the lowest rank of coal due to its relatively low heat content. When removed from the ground, it contains a very high amount of moisture, which partially explains its low carbon content. Lignite is mined all around the world and is used almost exclusively as a fuel for steam-electric power generation. Lignite combustion produces less heat for the amount of carbon dioxide and sulfur released than other ranks of coal. As a result, lignite is the most harmful coal to human health. Depending on the source, various toxic heavy metals, including naturally occurring radioactive materials, may be present in lignite and left over in the coal fly ash produced from its combustion, further increasing health risks. Characteristics Lignite is brownish-bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Libyan Desert Glass
Libyan desert glass or Great Sand Sea glass is an impactite, made mostly of lechatelierite, found in areas in the eastern Sahara, in the deserts of eastern Libya and western Egypt. Fragments of desert glass can be found over areas of tens of square kilometers. Like obsidian, it was knapped and used to make tools during the Pleistocene. Geologic origin The origin of desert glass is uncertain. Meteoritic origins have long been considered possible, and recent research links the glass to impact features, such as zircon breakdown, vaporized quartz and meteoritic metals, and to an impact crater. Some geologists associate the glass with radiative melting from meteoric large aerial bursts, making it analogous to trinitite created from sand exposed to the thermal radiation of a nuclear explosion. Libyan Desert glass has been dated as having formed about 29 million years ago. Analysis of samples with the electron backscatter diffraction (EBSD) technique revealed zircon Z ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonardite
Leonardite is a soft waxy, black or brown, shiny, vitreous mineraloid that is easily soluble in alkaline solutions. It is an oxidation product of lignite, associated with near-surface mining. It is a rich source of humic acid (up to 90%) and is used as a soil conditioner, as a stabilizer for ion-exchange resins in water treatment, in the remediation of Pollution, polluted environments and as a Well drilling, drilling additive.Hoffman, G.L., Nikols, D.J., Stuhec, S., Wilson, R.A. Evaluation of Leonardite (Humalite) Open File Report 1993-18, Resources of Alberta, Alberta Geological Survey It was named after A. G. Leonard, first director of the North Dakota Geological Sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lechatelierite
Lechatelierite is silica glass, amorphous SiO2, non-crystalline mineraloid. It is named for Henry Louis Le Chatelier. Structure Lechatelierite is a mineraloid as it does not have a crystal structure. Although not a true mineral, it is often classified in the quartz mineral group. Formation One common way in which lechatelierite forms naturally is by very-high-temperature melting of quartz sand during a lightning strike. The result is an irregular, branching, often foamy hollow tube of silica glass called a fulgurite. Not all fulgurites are lechatelierite; the original sand must be nearly pure silica. Lechatelierite also forms as the result of high pressure shock metamorphism during meteorite impact cratering and is a common component of a type of glassy ejecta called tektites. Most tektites are blobs of impure glassy material, but tektites from the Sahara Desert in Libya and Egypt, known as '' Libyan desert glass'', are composed of almost pure silica that is almost pure lech ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet (lignite)
Jet, Jets, or The Jet(s) may refer to: Aerospace * Jet aircraft, an aircraft propelled by jet engines ** Jet airliner ** Jet engine ** Jet fuel * Jet Airways, an Indian airline * Super Air Jet, an Indonesian airline * Wind Jet (ICAO: JET), an Italian airline * Journey to Enceladus and Titan (JET), a proposed astrobiology orbiter to Saturn * Jet pack, a backpack personal flying device containing a jet motor * Fighter jet, a military aircraft Aircraft * Business jet ** Boeing Business Jet * Very light jet ** Cirrus Vision SF50, originally called "The-Jet by Cirrus" ** Eclipse 400, originally called "Eclipse Concept Jet" ** Honda HA-420 HondaJet ** Piper PA-47 PiperJet Other areas of science, math, and technology * Jet (fluid), a coherent stream of fluid that is projected into a surrounding medium, usually from some kind of a nozzle or aperture * Jet (gemstone), a black or brown semi-precious mineraloid * Jet (mathematics), an operation on a differentiable function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fulgurite
Fulgurites (), commonly called "fossilized lightning", are natural tubes, clumps, or masses of sintered, vitrified, or fused soil, sand, rock, organic debris and other sediments that sometimes form when lightning discharges into ground. When composed of silica, fulgurites are classified as a variety of the mineraloid lechatelierite. When ordinary negative polarity cloud-ground lightning discharges into a grounding substrate, greater than 100 million volts (100 MV) of potential difference may be bridged. Such current may propagate into silica-rich quartzose sand, mixed soil, clay, or other sediments, rapidly vaporizing and melting resistant materials within such a common dissipation regime. This results in the formation of generally hollow and/or vesicular, branching assemblages of glassy tubes, crusts, and clumped masses. Fulgurites have no fixed composition because their chemical composition is determined by the physical and chemical properties of whatever material is bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ebonite
Ebonite is a brand name for a material generically known as hard rubber or vulcanite, obtained via vulcanizing natural rubber for prolonged periods. Ebonite may contain from 25% to 80% sulfur and linseed oil. Its name comes from its intended use as an artificial substitute for ebony wood. The material has also been called ''vulcanite'', although that name formally refers to the mineral vulcanite. Charles Goodyear's brother, Nelson Goodyear, experimented with the chemistry of ebonite composites. In 1851, he used zinc oxide as a filler. Hugh Silver was responsible for giving it its name. Properties The sulfur percentage and the applied temperatures and duration of vulcanizing are the main variables that determine the technical properties of the hard rubber polysulfide elastomer. The occurring reaction is basically addition of sulfur at the double bonds, forming intramolecular ring structures, so a large portion of the sulfur is highly cross-linked in the form of intramolecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatomite
Diatomaceous earth ( ), also known as diatomite ( ), celite, or kieselguhr, is a naturally occurring, soft, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 mm to less than 1 μm, but typically 10 to 200 μm. Depending on the granularity, this powder can have an abrasive feel, similar to pumice powder, and has a low density as a result of its high porosity. The typical chemical composition of oven-dried diatomaceous earth is 80–90% silica, with 2–4% alumina (attributed mostly to clay minerals), and 0.5–2% iron oxide. Diatomaceous earth consists of the fossilized remains of diatoms, a type of hard-shelled microalgae, that have accumulated over millions of years. It is used as a filtration aid, mild abrasive in products including metal polishes and toothpaste, mechanical insecticide, absorbent for liquids, matting agent for coatings, reinforcing filler in plastics and r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stevensite
Stevensite is a white clay mineral composed of hydrated calcium, sodium and magnesium silicate, with the chemical formula (Ca,Na)xMg3-x(Si4O10)(OH)2. The mineral is a member of smectite A smectite (; ; ) is a mineral mixture of various swelling sheet silicates (phyllosilicates), which have a three-layer 2:1 (TOT) structure and belong to the clay minerals. Smectites mainly consist of montmorillonite, but can often contain secon .... The mineral is named after Edwin Augustus Stevens. Stevensite can be found at the Dean Quarry. References {{Mineral-stub Smectite group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Talc
Talc, or talcum, is a clay mineral composed of hydrated magnesium silicate, with the chemical formula . Talc in powdered form, often combined with corn starch, is used as baby powder. This mineral is used as a thickening agent and lubricant. It is an ingredient in ceramics, paints, and roofing material. It is a main ingredient in many cosmetics. It occurs as foliated to fibrous masses, and in an exceptionally rare crystal form. It has a perfect basal cleavage and an uneven flat fracture, and it is foliated with a two-dimensional platy form. The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 1 as the hardness of talc, the softest mineral. When scraped on a streak plate, talc produces a white streak, though this indicator is of little importance, because most silicate minerals produce a white streak. Talc is translucent to opaque, with colors ranging from whitish grey to green with a vitreous and pearly luster. Talc is not soluble i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
