Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO3. In its pure form (rare), it is typically a rose-red colour, but it can also be shades of pink to pale brown. It streaks white, and its Mohs hardness varies between 3.5 and 4.5. Its specific gravity is between 3.45 and 3.6. The crystal system of rhodochrosite is trigonal, with a lattice structure and cleavage in the carbonate rhombohedral system. The carbonate ions (CO2−
3) are arranged in a triangular planar configuration, and the manganese ions (Mn2–) are surrounded by six oxygen ions in an octahedral arrangement. The MnO6 octahedra and CO3 triangles are linked together to form a three-dimensional structure. Crystal twinning is often present. It can be confused with the manganese silicate rhodonite, but is distinctly softer. Rhodochrosite is formed by the oxidation of manganese ore, and is found in South Africa, China, and the Americas. It is one of the national symbols of Argentina.
Thénardite is an anhydrous sodium sulfate mineral, Na2SO4 which occurs in arid evaporite environments, specifically lakes and playas. It also occurs in dry caves and old mine workings as an efflorescence and as a crusty sublimate deposit around fumaroles. It occurs in volcanic caves on Mount Etna, Italy. It was first described in 1825 for an occurrence in the Espartinas Saltworks, Ciempozuelos, Madrid, Spain and was named for the French chemist, Louis Jacques Thénard (1777–1826).
Lithiophilite is a mineral containing the element lithium. It is lithium manganese(II) phosphate with chemical formula LiMnPO4. It occurs in pegmatites often associated with triphylite, the iron end member in a solid solution series. The mineral with intermediate composition is known as sicklerite and has the chemical formula Li(Mn,Fe)PO4). The name lithiophilite is derived from the Greek philos (φιλός) "friend", as lithiophilite is usually found with lithium.
The Borate Minerals are minerals which contain a borate anion group. The borate (BO3) units may be polymerised similar to the SiO4 unit of the silicate mineral class. This results in B2O5, B3O6, B2O4 anions as well as more complex structures which include hydroxide or halogen anions. The [B(O,OH)4]− anion exists as well.
Warwickite is an iron magnesium titanium borate mineral with the chemical formula (MgFe)3Ti(O, BO3)2orMg(Ti,Fe3+, Al)(BO3)O. It occurs as brown to black prismatic orthorhombic crystals which are vitreous and transparent. It has a Mohs hardness of 3 to 4 and a specific gravity of 3.36.
Wagnerite is a mineral, a combined phosphate and fluoride of iron and magnesium, with the formula (Mg,Fe2+)2PO4F. It occurs in pegmatite associated with other phosphate minerals. It is named after Franz Michael von Wagner (1768–1851), a German mining official in Munich.
Sassolite is a borate mineral, specifically the mineral form of boric acid. It is usually white to gray, and colourless in transmitted light. It can also take on a yellow colour from sulfur impurities, or brown from iron oxides.
Seamanite, named for discoverer Arthur E. Seaman, is a rare manganese boron phosphate mineral with formula Mn3[B(OH)4](PO4)(OH)2. The yellow to pink mineral occurs as small, needle-shaped crystals. It was first discovered in 1917 from a mine in Iron County, Michigan, United States and identified in 1930. As of 2012, seamanite is known from four sites in Michigan and South Australia.
Howlite, a calcium borosilicate hydroxide (Ca2B5SiO9(OH)5), is a borate mineral found in evaporite deposits.
Meyerhofferite is a hydrated borate mineral of calcium, with the chemical formula Ca2B6O6(OH)10·2H2O, CaB3O3(OH)5·H2O or Ca2(H3B3O7)2·4H2O. It occurs principally as an alteration product of inyoite, another borate mineral.
Calciborite, CaB2O4, is a rare calcium borate mineral.
Chambersite is a manganese borate mineral with formula Mn3B7O13Cl. It is a member of the borate mineral series that includes other minerals such as ericaite and boracite. When chambersite was first discovered, it was the second chemical analogue of boracite to be found in nature. It was discovered as a mineral at Barber's Hill salt dome in Texas in 1957 and in 1971 at the Dongshuichang deposit in Jixian, Tianjin, China. Chambersite occurs associated with the evaporite minerals halite, anhydrite, and gypsum.
Bunsenite is the naturally occurring form of nickel(II) oxide, NiO. It occurs as rare dark green crystal coatings. It crystallizes in the cubic crystal system and occurs as well formed cubic, octahedral and dodecahedral crystals. It is a member of the periclase group.
Fluoborite has a chemical formula of Mg3(BO3)(F,OH)3. Its name comes from its main chemical components, fluorine and boron. It was first described in 1926.
Hambergite (Be2BO3OH) is a beryllium borate mineral named after Swedish explorer and mineralogist Axel Hamberg (1863–1933). The mineral occurs as white or colorless orthorhombic crystals.
Norbergite is a nesosilicate mineral with formula Mg3(SiO4)(F,OH)2. It is a member of the humite group.
Pinnoite is a magnesium borate mineral with formula: MgB2O(OH)6 or MgB2O4·3(H2O). It crystallizes in the tetragonal crystal system and occurs as colorless to yellow or light green radial fibrous clusters and rarely as short prismatic crystals.
Henry How was a British-Canadian chemist, geologist and mineralogist.
Argentojarosite is an iron sulfate mineral with the chemical formula AgFe3+3(SO4)2(OH)6. It is one of few iron sulfate minerals containing silver in its chemical formula as a dominant element. Its type locality is the East Tintic Mountains, Utah.
Foitite is a mineral in the tourmaline group, it is a vacancy-dominant member of the group. Foitite is in the 'vacancy' group, due to the absence of atoms in the X site.
