Chambersite is a

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

borate mineral 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 whic ...

with formula . It is a member of the borate mineral seriesGrice ''et al.'', 2005 that includes other minerals such as ericaite () and

boracite Boracite is a magnesium borate mineral with formula: Mg3 B7 O13 Cl. 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 fo ...

().Yawn ''et al.'', 1997 When chambersite was first discovered, it was the second chemical analogue of boracite to be found in nature.Honea ''et al.'', 1962 It was discovered as a mineral at Barber's Hill

salt dome A salt dome is a type of structural dome formed when salt (or other evaporite minerals) intrudes into overlying rocks in a process known as diapirism. Salt domes can have unique surface and subsurface structures, and they can be discovered us ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

in 1957 and in 1971 at the Dongshuichang deposit in Jixian,

Tianjin Tianjin is a direct-administered municipality in North China, northern China on the shore of the Bohai Sea. It is one of the National Central City, nine national central cities, with a total population of 13,866,009 inhabitants at the time of the ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

.Fan ''et al.'', 1999 Chambersite occurs associated with the

evaporite An evaporite () is a water- soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as oce ...

minerals

halite Halite ( ), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pi ...

anhydrite Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the ...

, and

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate Hydrate, dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk ...

Chemical and physical properties

When chambersite was first discovered in Barber's Hill, the dominant form was the positive

tetrahedron In geometry, a tetrahedron (: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular Face (geometry), faces, six straight Edge (geometry), edges, and four vertex (geometry), vertices. The tet ...

, but single morphological twinned crystal was found with interpenetrating tetrahedrons with the twinning axis. The ore discovered in China had formed in high grades that are spindle and granular that form micritic aggregates because the

boron Boron is a chemical element; it has symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the boron group it has three ...

present is very pure and in low grades that had formed spheroids that are radially oriented. When chambersite in China was compared it had the same chemical

oxide An oxide () is a chemical compound containing at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion (anion bearing a net charge of −2) of oxygen, an O2− ion with oxygen in the oxidation st ...

ratio as the samples found in Barber's Hill.

Geologic occurrence

Chambersite minerals were first found in 1957 in

brine Brine (or briny water) is a high-concentration solution of salt (typically sodium chloride or calcium chloride) in water. In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawat ...

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 The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

and possibly upper

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

. Other chambersite deposits with this similar geologic occurrence can be found in the area of the

Gulf Coast The Gulf Coast of the United States, also known as the Gulf South or the South Coast, is the coastline along the Southern United States where they meet the Gulf of Mexico. The coastal states that have a shoreline on the Gulf of Mexico are Tex ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

.Smith ''et al.'', 1994 The Venice dome in

Plaquemines Parish, Louisiana Plaquemines Parish ( ; ; ; ) is a Parish (subnational entity), parish located in the U.S. state of Louisiana. With a population of 23,515 at the 2020 United States census, 2020 census, the parish seat is Pointe à la Hache, Louisiana, Pointe � ...

is a site that has a shallow piercement salt dome, LPG storage and brine production. Other chambersite deposits can be found in the Penobsquis deposit in Southern

New Brunswick New Brunswick is a Provinces and Territories of Canada, province of Canada, bordering Quebec to the north, Nova Scotia to the east, the Gulf of Saint Lawrence to the northeast, the Bay of Fundy to the southeast, and the U.S. state of Maine to ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, which has high grade salt deposits as well as a significant borate mineral concentration, including chambersite. Other chambersite deposits can be found as ores in

Ji County, Tianjin Jizhou District (), formerly a county known as Ji County, is a district in the far north of the municipality of Tianjin, People's Republic of China, holding cultural and historical significance (''e.g''., the Buddhist Temple of Solitary Joy). O ...

, an area that is known to have had much

magnetic Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel each other. Because both electric currents and magnetic moments of elementary particles give rise to a magnetic field, m ...

activity and submarine

volcanism Volcanism, vulcanism, volcanicity, or volcanic activity is the phenomenon where solids, liquids, gases, and their mixtures erupt to the surface of a solid-surface astronomical body such as a planet or a moon. It is caused by the presence of a he ...

in a subtidal

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

Special characteristics

Chambersite was named after the county where it was first discovered, Chambers County, Texas, US. Optical examination and x-ray powder diffraction indicated the mineral to be related to boracite but different from any other published description.

References

* Anthony, J.W., Bidideaux, R., Bladh, K. and Nicholas, M. (2003
Chambersite Mn₃B₇O₁₃Cl
Handbook of Mineralogy. Mineral data publishing * Fan, DL, Yang, PJ, and Wang, R (1999) Characteristics and origin of the Middle Proterozoic Dongshuichang chambersite deposit, Jixan, Tixian, Tianjin, China. Ore Geology Reviews, 15, 15-29.] * Grice, J. D., Gault, R. A., van Velthuizen, J. (2005) Borate minerals of the Penobsquis and Millstream deposit, southern New Brunswick, Canada. Canadian Mineralogist, 43, 1469-1488.] * Honea, Russell M., Beck, Frank R. (1962
Chamersite, a new mineral

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 Mi ...

, 47, 665-671. * Smith, Arthur E., Jr. (1994) Louisiana mineral locality index. Rock and Mineral, 69, 156-162.] * Yawn, B., Simmons, W. B., Falster, A. U. (1997) Chemical Zonation in Chambersite and Boraciate from salt domes in the Gulf Coast region. Rock and Minerals, 72, 192. {{Commons category Manganese(II) minerals Tektoborates Chloride minerals Orthorhombic minerals Minerals in space group 29 Minerals described in 1957 Borate chlorides

Chemical and physical properties

Geologic occurrence

Special characteristics

See also

References