Chambersite | |
---|---|
General | |
Category | Tektoborates |
Formula (repeating unit) | Mn3B7O13Cl |
IMA symbol | Cbs [1] |
Strunz classification | 6.GA.05 |
Crystal system | Orthorhombic |
Crystal class |
|
Space group | Pca21 |
Identification | |
Color | Colorless to deep purple |
Crystal habit | Pseudocubic crystals |
Twinning | Rare as interpenetration twins on [111] |
Cleavage | None |
Fracture | Subconchoidal to uneven |
Mohs scale hardness | 7 |
Luster | Vitreous |
Diaphaneity | Transparent to opaque |
Specific gravity | 3.49 |
Optical properties | Biaxial (+) |
Refractive index | nα = 1.732 nβ = 1.737 nγ = 1.744 |
Birefringence | δ = 0.012 |
2V angle | Measured: 83° |
Dispersion | r > v |
Alters to | Color darkens when exposed to sunlight |
References | [2] [3] [4] |
Chambersite is a manganese borate mineral with formula Mn3B7O13Cl. It is a member of the borate mineral series [5] that includes other minerals such as ericaite (Fe3B7O13Cl) and boracite (Mg3B7O13Cl). [6] When chambersite was first discovered, it was the second chemical analogue of boracite to be found in nature. [7] 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. [8] Chambersite occurs associated with the evaporite minerals halite, anhydrite, and gypsum. [7]
When chambersite was first discovered in Barber's Hill, the dominant form was the positive tetrahedron, but single morphological twinned crystal was found with interpenetrating tetrahedrons with the twinning axis. [7] The ore discovered in China had formed in high grades that are spindle and granular that form micritic aggregates because the boron present is very pure and in low grades that had formed spheroids that are radially oriented. [8] When chambersite in China was compared it had the same chemical oxide ratio as the samples found in Barber's Hill. [8]
Oxide | Chemical composition of chambersite in oxide percent [7] |
---|---|
B2O3 | 49.50 |
MnO | 41.87 |
Cl | 6.34 |
FeO | 1.28 |
MgO | 0.05 |
CaO | trace |
Total % | 99.04 |
Chambersite minerals were first found in 1957 in brine returns from a gas storage well in the Barber's Hill salt dome. The age of the dome is not definitely known, but it is at least dates back to the Cretaceous and possibly upper Jurassic. [7] Other chambersite deposits with this similar geologic occurrence can be found in the area of the Gulf Coast of Mexico. [9] The Venice dome in Plaquemines Parish, Louisiana is a site that has a shallow piercement salt dome, LPG storage and brine production. [9] Other chambersite deposits can be found in the Penobsquis deposit in Southern New Brunswick, Canada, which has high grade salt deposits as well as a significant borate mineral concentration, including chambersite. [5] Other chambersite deposits can be found as ores in Ji County, Tianjin, China, an area that is known to have had much magnetic activity and submarine volcanism in a subtidal lagoon. [8]
Chambersite was named after the county where it was first discovered, Chambers County, Texas, US. [7] Optical examination and x-ray powder diffraction indicated the mineral to be related to boracite but different from any other published description. [7]
Ulexite (NaCaB5O6(OH)6·5H2O, hydrated sodium calcium borate hydroxide), sometimes known as TV rock or television stone, is a mineral occurring in silky white rounded crystalline masses or in parallel fibers. The natural fibers of ulexite conduct light along their long axes, by internal reflection. Ulexite was named for the German chemist Georg Ludwig Ulex (1811–1883) who first discovered it.
Vanadinite is a mineral belonging to the apatite group of phosphates, with the chemical formula Pb5(VO4)3Cl. It is one of the main industrial ores of the metal vanadium and a minor source of lead. A dense, brittle mineral, it is usually found in the form of red hexagonal crystals. It is an uncommon mineral, formed by the oxidation of lead ore deposits such as galena. First discovered in 1801 in Mexico, vanadinite deposits have since been unearthed in South America, Europe, Africa, and North America.
Alforsite is a barium phosphate chloride mineral with formula: Ba5(PO4)3Cl. It was discovered in 1981, and named to honor geologist John T. Alfors (1930–2005) of the California Geological Survey for his work in the area where it was discovered.
Halite, commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride (NaCl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on inclusion of other materials, impurities, and structural or isotopic abnormalities in the crystals. It commonly occurs with other evaporite deposit minerals such as several of the sulfates, halides, and borates. The name halite is derived from the Ancient Greek word for "salt", ἅλς (háls).
Boracite is a magnesium borate mineral with formula: Mg3B7O13Cl. It occurs as blue green, colorless, gray, yellow to white crystals in the orthorhombic - pyramidal crystal system. Boracite also shows pseudo-isometric cubical and octahedral forms. These are thought to be the result of transition from an unstable high temperature isometric form on cooling. Penetration twins are not unusual. It occurs as well formed crystals and dispersed grains often embedded within gypsum and anhydrite crystals. It has a Mohs hardness of 7 to 7.5 and a specific gravity of 2.9. Refractive index values are nα = 1.658 - 1.662, nβ = 1.662 - 1.667 and nγ = 1.668 - 1.673. It has a conchoidal fracture and does not show cleavage. It is insoluble in water (not to be confused with borax, which is soluble in water).
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.
Hilgardite is a borate mineral with the chemical formula Ca2B5O9Cl·H2O. It is transparent and has vitreous luster. It is colorless to light pink with a white streak. It is rated 5 on the Mohs Scale. It crystallizes in the triclinic crystal system. Crystals occur as distorted tabular triangles and are hemimorphic, polytypes exist.
Mosesite is a very rare mineral found in few locations. It is a mercury mineral found as an accessory in deposits of mercury, often in conjunction with limestone. It is known to be found in the U.S. states of Texas and Nevada, and the Mexican states of Guerrero and Querétaro. It was named after Professor Alfred J. Moses (1859–1920) for his contributions to the field of mineralogy in discovering several minerals found alongside mosesite. The mineral itself is various shades of yellow and a high occurrence of spinel twinning. It becomes isotropic when heated to 186 °C (367 °F).
Kurnakovite is a hydrated borate of magnesium with the chemical composition MgB3O3(OH)5·5H2O. It is a member of the inderite group and is a triclinic dimorph of the monoclinic inderite.
Kampfite is a rare barium silicate–carbonate–halide mineral with the chemical formula Ba12(Si11Al5)O31(CO3)8Cl5. Discovered in 1964 and described in 2001, it is named after Anthony R. Kampf. The mineral is known only from Fresno County, California.
Chamosite is the Fe2+end member of the chlorite group. A hydrous aluminium silicate of iron, which is produced in an environment of low to moderate grade of metamorphosed iron deposits, as gray or black crystals in oolitic iron ore. Like other chlorites, it is a product of the hydrothermal alteration of pyroxenes, amphiboles and biotite in igneous rock. The composition of chlorite is often related to that of the original igneous mineral so that more Fe-rich chlorites are commonly found as replacements of the Fe-rich ferromagnesian minerals (Deer et al., 1992).
Coloradoite, also known as mercury telluride (HgTe), is a rare telluride ore associated with metallic deposit. Gold usually occurs within tellurides, such as coloradoite, as a high-finess native metal.
Gugiaite is a melilite mineral, named for the Chinese village of Gugia where it was first discovered. Its chemical formula is Ca2BeSi2O7. It occurs mostly in skarns with melanite adjacent to an alkali syenite and has no economic value. Its crystals are small tetragonal tablets with vitreous luster and perfect cleavage. It is colorless and transparent with a density of three. The mineral belongs to space group P-421m and is strongly piezoelectric.
The mineral hubeite, Ca
2Mn2+
Fe3+
[Si
4O
12(OH)]·(H
2O)
2, is a sorosilicate of the Si
4O
13 group. Structurally it also belongs to the Akatoreite group. It was found and named after the province of Hubei, China. It is common to iron ores in a mine of that region. It occurs mainly as aggregates of fan like crystals. It is dark to pale brown, has orange-brown streak and is vitreous. Hubeite has a hardness of 5.5 in the Mohs scale, one good cleavage and conchoidal fracture. It is triclinic with a space group of P1*. The structure of hubeite is very uncommon, and in fact there is only one other mineral that fits the Si
4O
13 group, which is ruizite.
Xitieshanite is a hydrous iron sulfate–chloride mineral with chemical formula: Fe3+(SO4)Cl·6(H2O).
Leonite is a hydrated double sulfate of magnesium and potassium. It has the formula K2SO4·MgSO4·4H2O. The mineral was named after Leo Strippelmann, who was director of the salt works at Westeregeln in Germany. The mineral is part of the blodite group of hydrated double sulfate minerals.
Henry How was a British-Canadian chemist, geologist and mineralogist.
Hans Peter Eugster was a Swiss-American geochemist, mineralogist, and petrologist.
Alloriite is a silicate mineral that belongs to the cancrinite group, or more specifically the feldspathoid group. It is currently only found in Italy. It was discovered by and named for the Italian mineralogist Roberto Allori, an avid mineral collector who has also done research on piergorite and willhendersonite. The mineral appears as a crystal that is approximately 1.5 by 2mm in length. The crystal grows as both tabular and prismatic crystals, and commonly occurs with sanidine, biotite, andradite, and apatite. It was approved of being a mineral in 2006 by the International Mineralogical Association. Afghanite is a cancrinite group mineral that is very similar to alloriite in both its chemical composition and its physical properties.
John Leslie Jambor was a Canadian geologist and mineralogist. Jambor was an exceptional figure in the field of mineralogy and a major contributor to the Mineralogical Association of Canada (MAC).
Jambor has a Scopus h-index of 38.