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Thomsenolite and Ralstonite - Ivittuut, Arsuk Firth, Kitaa. West Greenland.jpg
Thomsenolite (obelisks) and some pseudocubic ralstonite (picture center)
Category Halide minerals
(repeating unit)
IMA symbol Tse [1]
Strunz classification 3.CB.40
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H-M symbol)
Space group P21/b
ColorColourless, white, pale lilac; brownish or reddish tinted due to staining; colourless in transmitted light.
Cleavage Perfect
On {001}; {110} distinct.
Fracture Irregular/ uneven
Tenacity Brittle
Mohs scale hardness2
Lustre Vitreous, pearly
Streak White
Diaphaneity Transparent, translucent
Density 2.981 g/cm3

Thomsenolite is a mineral with formula: NaCaAlF6·H2O. It is an alteration product of cryolite. [2]

It was discovered in 1868 in Ivigtut, Greenland and named for Hans Peter Jorgen Julius Thomsen (1826–1909). [3]

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<span class="mw-page-title-main">Augite</span> Common rock-forming pyroxene mineral

Augite is a common rock-forming pyroxene mineral with formula (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6. The crystals are monoclinic and prismatic. Augite has two prominent cleavages, meeting at angles near 90 degrees.

<span class="mw-page-title-main">Acanthite</span> Mineral, silver sulfide

Acanthite is a form of silver sulfide with the chemical formula Ag2S. It crystallizes in the monoclinic system and is the stable form of silver sulfide below 173 °C (343 °F). Argentite is the stable form above that temperature. As argentite cools below that temperature its cubic form is distorted to the monoclinic form of acanthite. Below 173 °C acanthite forms directly. Acanthite is the only stable form in normal air temperature.

<span class="mw-page-title-main">Chalcocite</span> Sulfide mineral

Chalcocite, copper(I) sulfide (Cu2S), is an important copper ore mineral. It is opaque and dark gray to black, with a metallic luster. It has a hardness of 2.5–3 on the Mohs scale. It is a sulfide with a monoclinic crystal system.

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

Zinnwaldite, KLiFeAl(AlSi3)O10(OH,F)2, potassium lithium iron aluminium silicate hydroxide fluoride is a silicate mineral in the mica group. The IMA status is as a series between siderophyllite (KFe2Al(Al2Si2)O10(F,OH)2) and polylithionite (KLi2AlSi4O10(F,OH)2) and not considered a valid mineral species.

<span class="mw-page-title-main">Aegirine</span> Member of the clinopyroxene group of inosilicate mineral

Aegirine is a member of the clinopyroxene group of inosilicate minerals. Aegirine is the sodium endmember of the aegirine-augite series. Aegirine has the chemical formula NaFeSi2O6 in which the iron is present as Fe3+. In the aegirine-augite series the sodium is variably replaced by calcium with iron(II) and magnesium replacing the iron(III) to balance the charge. Aluminium also substitutes for the iron(III). Acmite is a fibrous, green-colored variety.

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

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.

<span class="mw-page-title-main">Cancrinite</span> Feldspathoid mineral

Cancrinite is a complex carbonate and silicate of sodium, calcium and aluminium with the formula Na6Ca2[(CO3)2|Al6Si6O24]·2H2O. It is classed as a member of the feldspathoid group of minerals; the alkali feldspars that are poor in silica. Yellow, orange, pink, white or even blue, it has a vitreous or pearly luster; a hardness of 5–6 and an uneven conchoidal fracture. It is unusual among the silicate minerals in that it will effervesce with hydrochloric acid due to the associated carbonate ions.

<span class="mw-page-title-main">Calderite</span> Mineral in the garnet group

Calderite is a mineral in the garnet group with the chemical formula (Mn2+, Ca)3(Fe3+, Al)2(SiO4)3.

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

Triploidite is an uncommon manganese iron phosphate mineral with formula: (Mn, Fe)2PO4OH. It crystallizes in the monoclinic crystal system and typically occurs as elongated and striated slender prisms which may be columnar to fibrous. Its crystals may be pinkish to yellowish brown or red-orange.

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

Chloritoid is a silicate mineral of metamorphic origin. It is an iron magnesium manganese alumino-silicate hydroxide with formula (Fe, Mg, Mn)
. It occurs as greenish grey to black platy micaceous crystals and foliated masses. Its Mohs hardness is 6.5, unusually high for a platy mineral, and it has a specific gravity of 3.52 to 3.57. It typically occurs in phyllites, schists and marbles.

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

Jacobsite is a manganese iron oxide mineral. It is in the spinel group and forms a solid solution series with magnetite. The chemical formula is (Mn,Mg)Fe2O4 or with oxidation states and substitutions: (Mn2+,Fe2+,Mg)(Fe3+,Mn3+)2O4.

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

Zabuyelite is the natural mineral form of lithium carbonate, with a formula Li2CO3. It was discovered in 1987 at Lake Zabuye, Tibet, after which it is named. It forms colorless vitreous monoclinic crystals.

Zincobotryogen is a hydrous sulfate mineral with the chemical formula (Zn,Mg,Mn)Fe3+(SO4)2(OH)·7H2O. It forms bright orange red monoclinic prismatic crystals that exhibit a vitreous to greasy luster. Its specific gravity is 2.201 and it has a Mohs hardness of 2.5.

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

Zirconolite is a mineral, calcium zirconium titanate; formula CaZrTi2O7. Some examples of the mineral may also contain thorium, uranium, cerium, niobium and iron; the presence of thorium or uranium would make the mineral radioactive. It is black or brown in color.

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

Neptunite is a silicate mineral with the formula KNa2Li(Fe2+, Mn2+)2Ti2Si8O24. With increasing manganese it forms a series with mangan-neptunite. Watatsumiite is the variety with vanadium replacing the titanium in the formula.

<span class="mw-page-title-main">Hectorite</span> Rare trioctahedral (Mg2+, Li+) sodium smectite, phyllosilicate mineral

Hectorite is a rare soft, greasy, white clay mineral with a chemical formula of Na0.3(Mg,Li)3Si4O10(OH)2.

Anandite is a rare phyllosilicate with formula (Ba,K)(Fe2+,Mg)3(Si,Al,Fe)4O10(S,OH)2. It crystallizes in the monoclinic crystal system. It is black in color with a glassy luster and a near perfect cleavage.

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

Stilpnomelane is a phyllosilicate mineral. It has the chemical formula K(Fe2+,Mg,Fe3+)8(Si,Al)12(O,OH)27·n(H2O).

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

Manganosite is a rare mineral composed of manganese(II) oxide MnO. It was first described in 1817 for an occurrence in the Harz Mountains, Saxony-Anhalt, Germany. It has also been reported from Langban and Nordmark, Sweden and at Franklin Furnace, New Jersey. It also occurs in Japan, Kyrgyzstan and Burkina Faso.


  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.
  2. Handbook of Mineralogy
  3. entry