Last updated
Category Nesoborates
(repeating unit)
IMA symbol Tnc [1]
Strunz classification 6.DA.15
Crystal system Trigonal
Crystal class Trapezohedral (32)
H-M symbol: (32)
Space group R32

Tincalconite is a hydrous sodium borate mineral closely related to borax, and is a secondary mineral that forms as a dehydration product of borax. Its formula is Na 2 B 4 O 7·5H2O or Na2[B4O5(OH)4]·3H2O.

Tincalconite typically occurs as a fine grained white powder. It crystallizes in the hexagonal crystal system and has been found as primary euhedral di-rhombohedral, pseudo-octahedral crystals. It is also found pseudomorphically replacing borax crystals. It has a specific gravity of 1.88 and a Mohs hardness of 2. Refractive index values are nω=1.460 and nε=1.470.

While most tincalconite is created by man through exposing borax to dry air, there are natural occurrences of tincalconite, as in Searles Lake, California where it was first described in 1878. In addition to several California and Nevada locations it is reported from Argentina, Italy, Turkey and Ukraine.

The name comes from "tincal", Sanskrit for borax, and Greek, "konis", meaning powder, for its composition and typical powdery nature.

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Kernite, also known as rasorite, is a hydrated sodium borate hydroxide mineral with formula Na
. It is a colorless to white mineral crystallizing in the monoclinic crystal system typically occurring as prismatic to acicular crystals or granular masses. It is relatively soft with Mohs hardness of 2.5 to 3 and light with a specific gravity of 1.91. It exhibits perfect cleavage and a brittle fracture.

<span class="mw-page-title-main">Ulexite</span>

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.

<span class="mw-page-title-main">Stilbite</span>

Stilbite is the name of a series of tectosilicate minerals of the zeolite group. Prior to 1997, stilbite was recognized as a mineral species, but a reclassification in 1997 by the International Mineralogical Association changed it to a series name, with the mineral species being named:

<span class="mw-page-title-main">Colemanite</span> Borate mineral

Colemanite (Ca2B6O11·5H2O) or (CaB3O4(OH)3·H2O) is a borate mineral found in evaporite deposits of alkaline lacustrine environments. Colemanite is a secondary mineral that forms by alteration of borax and ulexite.

<span class="mw-page-title-main">Boracite</span>

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).

<span class="mw-page-title-main">Apophyllite</span> Phyllosilicate mineral

The name apophyllite refers to a specific group of phyllosilicates, a class of minerals. Originally, the group name referred to a specific mineral, but was redefined in 1978 to stand for a class of minerals of similar chemical makeup that comprise a solid solution series, and includes the members fluorapophyllite-(K), fluorapophyllite-(Na), hydroxyapophyllite-(K). The name apophyllite is derived from the Greek ἀποφυλλίζω apophylliso, meaning "it flakes off", a reference to this class's tendency to flake apart when heated, due to water loss. Exfoliation of apophyllite is also possible by treating it with acids or simply by rubbing it. These minerals are typically found as secondary minerals in vesicles in basalt or other volcanic rocks. A recent change (2008) in the nomenclature system used for this group was approved by the International Mineralogical Association, removing the prefixes from the species names and using suffixes to designate the species. A subsequent nomenclature change approved by the International Mineralogical Association in 2013 renamed the minerals to include both suffixes and prefixes, as shown above.

<span class="mw-page-title-main">Hanksite</span>

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<span class="mw-page-title-main">Kurnakovite</span>

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<span class="mw-page-title-main">Lavendulan</span>

Lavendulan is an uncommon copper arsenate mineral, known for its characteristic intense electric blue colour. It belongs to the lavendulan group, which has four members:

<span class="mw-page-title-main">Nambulite</span>

Nambulite is a lithium bearing manganese silicate mineral with the chemical formula (Li,Na)Mn4Si5O14(OH). It is named after the mineralogist, Matsuo Nambu (born 1917) of Tohoko University, Japan, who is known for his research in manganese minerals. The mineral was first discovered in the Funakozawa Mine of northeastern Japan, a metasedimentary manganese ore.

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.

Farneseite is a mineral from the cancrinite sodalite group with 14 layer stacking. It is a complex silicate mineral with formula (Na,Ca,K)56(Al6Si6O24)7(SO4)12·6H2O. It was named after a location in Farnese, Lazio, Italy. It is a member of the cancrinite-sodalite group, approved in 2004 as a new mineral species. The group is characterized by the number of stacking layers making up each member, with farneseite being one of newest minerals in the group with a 14 layer stacking structure. It is a clear transparent mineral and has a hexagonal crystal system with crystal class of 6/m and space group of P63/m. The specimens discovered in Farnese were in a pyroclastic rock from the Làtera Cauldera region.

<span class="mw-page-title-main">Pinnoite</span>

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.

Scotlandite is a sulfite mineral first discovered in a mine at Leadhills in South Lanarkshire, Scotland, an area known to mineralogists and geologists for its wide range of different mineral species found in the veins that lie deep in the mine shafts. This specific mineral is found in the Susanna vein of Leadhills, where the crystals are formed as chisel-shaped or bladed. Scotlandite was actually the first naturally occurring sulfite, which has the ideal chemical formula of PbSO3. The mineral has been approved by the Commission on New Minerals and Mineral Names, IMA, to be named scotlandite for Scotland.

Lahnsteinite is a basic sulfate mineral first discovered in the Friedrichssegen Mine, Germany in a goethite cavity. Though found in goethite, the crystals of Lahnsteinite are few millimeters in size, and are tabular shaped. Lahnsteinite was the first mineral discovered in the Lahn Valley deposits. The empirical formula for lahnsteinite is (Zn3.3,Fe0.27,Cu0.11)3.91(S0.98O4)(OH)5*3H2.10O.

Lemanskiite is a mineral that was first discovered in a mine at Abundancia mine, El Guanaco mining district, Chile, with the ideal formula of NaCaCu5(AsO4)4Cl•3H2O. Originally, this mineral was discovered as being dimorphus with lavendulan, but in 2018 it was revised to only have 3 water molecules. Lemanskiite typically occurs as rosette-shaped aggregates of thin lamellar or needle-shaped aggregates, such as lammerite. Lemanskiite is dark sky blue with a light blue streak, it is brittle with an excellent cleavage plane. It was found on a dumping site in the abandoned Abundancia mine, El Guanaco mining district, Region II, Antofagasta Province, Chile The new mineral has been named after Chester S. Lemanski, Jr. This mineral and name were then approved by the Commission on New Minerals and Mineral Names of the International Mineralogical Association.

<span class="mw-page-title-main">Edoylerite</span>

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<span class="mw-page-title-main">Borax (mineral)</span> Borate mineral

Borax is a borate mineral found in evaporite deposits of alkaline lacustrine environments and as a surface efflorescence in arid regions. It is the chief mineral mined from the deposits at Boron, California and nearby locations, and is the chief source of commercial borax.


  1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi: 10.1180/mgm.2021.43 . S2CID   235729616.