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Tinaksite, Charoite-543035.png
Tinaksite (brown) and associated charoite (lilac).
Category Silicate mineral
(repeating unit)
IMA symbol Tnk [1]
Strunz classification 9.DG.75
Crystal system Triclinic
Crystal class Pinacoidal (1)
(same H-M symbol)
Space group P1
ColorPink, pale yellow, light brown
Crystal habit Fibrous, crystalline or prismatic, crystalline, or radial, crystalline
Cleavage Perfect in one direction, indistinct in one direction
Mohs scale hardness6
Luster Vitreous to glassy
Streak White
Diaphaneity Transparent to translucent
Specific gravity 2.82
Optical propertiesBiaxial (+)
Refractive index nα = 1.593 nβ = 1.621 nγ = 1.666
Birefringence δ = 0.073
References [2] [3] [4]

Tinaksite (chemical formula K2Na(Ca,Mn2+)2TiO[Si7O18(OH)]) [3] is a mineral found in northern Russia. Tinaksite can be grayish-white, yellowish, orange, or brown, [2] and it is often found in charoite. [5] Its name is derived from its composition: titanium (Ti), sodium (Na) potassium (K) and silicon (Si). The International Mineralogical Association first recognized tinaksite as a mineral in 1965.

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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">Abenakiite-(Ce)</span> Cyclosilicate mineral

Abenakiite-(Ce) is a mineral of sodium, cerium, neodymium, lanthanum, praseodymium, thorium, samarium, oxygen, sulfur, carbon, phosphorus, and silicon with a chemical formula Na26Ce6(SiO3)6(PO4)6(CO3)6(S4+O2)O. The silicate groups may be given as the cyclic Si6O18 grouping. The mineral is named after the Abenaki, an Algonquian Indian tribe of New England. Its Mohs scale rating is 4 to 5.

<span class="mw-page-title-main">Aenigmatite</span> Sapphirine supergroup, single chain inosilicate mineral

Aenigmatite, also known as Cossyrite after Cossyra, the ancient name of Pantelleria, is a sodium, iron, titanium inosilicate mineral. The chemical formula is Na2Fe2+5TiSi6O20 and its structure consists of single tetrahedral chains with a repeat unit of four and complex side branches. It forms brown to black triclinic lamellar crystals. It has Mohs hardness of 5.5 to 6 and specific gravity of 3.74 to 3.85. Aenigmatite forms a solid-solution series with wilkinsonite, Na2Fe2+4Fe3+2Si6O20.

<span class="mw-page-title-main">Lorenzenite</span> Sodium titanium silicate mineral

Lorenzenite is a rare sodium titanium silicate mineral with the formula Na2Ti2Si2O9 It is an orthorhombic mineral, variously found as colorless, grey, pinkish, or brown crystals.

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

Yuksporite is a rare inosilicate mineral with double width, unbranched chains, and the complicated chemical formula K4(Ca,Na)14Sr2Mn(Ti,Nb)4(O,OH)4(Si6O17)2(Si2O7)3(H2O,OH)3. It contains the relatively rare elements strontium, titanium and niobium, as well as the commoner metallic elements potassium, calcium, sodium and manganese. As with all silicates, it contains groups of linked silicon and oxygen atoms, as well as some associated water molecules.

Alluaivite is a rare mineral of the eudialyte group, with complex formula written as Na19(Ca,Mn)6(Ti,Nb)3Si26O74Cl·2H2O. It is unique among the eudialyte group as the only titanosilicate (other representatives of the group are usually zirconosilicates). The two dual-nature minerals of the group, being both titano- and zirconosilicates, are labyrinthite and dualite. They both contain alluaivite module in their structures. Alluaivite is named after Mt. Alluaiv in Lovozero Tundry massif, Kola Peninsula, Russia, where it is found in ultra-agpaitic, hyperalkaline pegmatites.

Alsakharovite-Zn (IMA symbol: Ask-Zn) is an extremely rare alkaline strontium zinc titanium silicate mineral from the cyclosilicates class, with the chemical formula NaSrKZn(Ti,Nb)4(Si4O12)2(O,OH)4·7H2O, from alkaline pegmatites. It belongs to the labuntsovite group.

Altisite (IMA symbol: Ati) is an exceedingly rare alkaline titanium aluminosilicate chloride mineral with formula Na3K6Ti2Al2Si8O26Cl3, from alkaline pegmatites. It is named after its composition (ALuminium, TItanium, and SIlicon).

<span class="mw-page-title-main">Kaersutite</span> Calcic titanium bearing amphibole mineral

Kaersutite is a dark brown to black double chain calcic titanium bearing amphibole mineral with formula: NaCa2(Mg3Ti4+Al)(Si6Al2)O22(O)2.

Nabalamprophyllite has a general formula of Ba(Na,Ba){Na3Ti[Ti2O2Si4O14](OH,F)2}. The name is given for its composition and relation to other lamprophyllite-group minerals. Lamprophyllite is a rare Ti-bearing silicate mineral usually found in intrusive igneous rocks.

Eveslogite is a complex inosilicate mineral with a chemical formula (Ca,K,Na,Sr,Ba)
found on Mt. Eveslogchorr in Khibiny Mountains, on the Kola peninsula, Russia. It was named after the place it was found. This silicate mineral occurs as an anchimonomineral veinlet that cross-cuts poikilitic nepheline syenite. This mineral appears to resemble yuksporite, as it forms similar placated fine fibrous of approximately 0.05 to 0.005mm that aggregates outwardly. The color of eveslogite is yellow or rather light brown. In addition, it is a semitransparent mineral that has a white streak and a vitreous luster. Its crystal system is monoclinic and possesses a hardness (Mohs) of 5. This newly discovered mineral belongs to the astrophyllite group of minerals and contains structures that are composed of titanosilicate layers. Limited information about this mineral exists due to the few research studies carried out since its recent discovery.

<span class="mw-page-title-main">Ikranite</span> Mineral member of the eudialyte group

Ikranite is a member of the eudialyte group, named after the Shubinov Institute of Crystallography of the Russian Academy of Sciences. It is a cyclosilicate mineral that shows trigonal symmetry with the space group R3m, and is often seen with a pseudo-hexagonal habit. Ikranite appears as translucent and ranges in color from yellow to a brownish yellow. This mineral ranks a 5 on Mohs Scale of Hardness, though it is considered brittle, exhibiting conchoidal fracture when broken.

Dualite is a very rare and complex mineral of the eudialyte group, its complexity being expressed in its formula Na
. The formula is simplified as it does not show the presence of cyclic silicate groups. The name of the mineral comes from its dual nature: zircono- and titanosilicate at once. Dualite has two modules in its structure: alluaivite one and eudialyte one. After alluaivite and labyrinthite it stands for third representative of the eudialyte group with essential titanium.

Labyrinthite is a very rare mineral of the eudialyte group. When compared to other species in the group, its structure is extremely complex - with over 100 sites and about 800 cations and anions - hence its name, with its complexity expressed in its chemical formula (Na,K,Sr)35Ca12Fe3Zr6TiSi51O144(O,OH,H2O)9Cl3. The formula is simplified as it does not show the presence of cyclic silicate groups. Complexity of the structure results in symmetry lowering from the typical centrosymmetrical group to R3 space group. Other eudialyte-group representatives with such symmetry lowering include aqualite, oneillite, raslakite, voronkovite. Labyrinthite is the second dual-nature representative of the group after dualite and third with essential titanium after dualite and alluaivite.

<span class="mw-page-title-main">Rastsvetaevite</span> Mineral of the eudialyte group

Rastsveatevite is a rare mineral of the eudialyte group with the chemical formula Na27K8Ca12Fe3Zr6Si4[Si3O9]4[Si9O27]4(O,OH,H2O)6Cl2. Its structure is modular. It is only the third member of the group after andrianovite and davinciite with essential (site-dominating) potassium. Potassium and sodium enter both N4 and M2 sites. The mineral is named after Russian crystallographer Ramiza K. Rastsvetaeva.

Faizievite is a very rare mineral with the formula K2Na(Ca6Na)Ti4Li6Si24O66F2. This triclinic mineral is chemically related to baratovite and katayamalite. Faizievite is a single-locality mineral, coming from the moraine of the Darai-Pioz glacier, Tien Shan Mountains, Tajikistan. Alkaline rocks of this site are famous for containing numerous rare minerals, often enriched in boron, caesium, lithium, titanium, rare earth elements, barium, and others.

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

Jinshajiangite is a rare silicate mineral named after the Jinshajiang river in China. Its currently accepted formula is BaNaFe4Ti2(Si2O7)2O2(OH)2F. It gives a name of the jinshajiangite group. The mineral is associated with alkaline rocks. In jinshajiangite, there is a potassium-to-barium, calcium-to-sodium, manganese-to-iron and iron-to-titanium diadochy substitution. Jinshajiangite is the iron-analogue of surkhobite and perraultite. It is chemically related to bafertisite, cámaraite and emmerichite. Its structure is related to that of bafertisite. Jinshajiangite is a titanosilicate with heteropolyhedral HOH layers, where the H-layer is a mixed tetrahedral-octahedral layer, and the O-layer is simply octahedral.

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

Seidozerite is a sorosilicate from the seidozerite supergroup (a "titanium disilicate"). It was first described by Semenov, Kazakova and Simonov in 1958. Its chemical formula is Na4MnZr2Ti(Si2O7)2O2F2 and its type locality is 'Pegmatite No. 58', Lake Seydozero, Lovozero massif, Kola peninsula, Murmansk Oblast.

<span class="mw-page-title-main">Lamprophyllite</span> Ti-silicate mineral

Lamprophyllite is a rare, but widespread mineral Ti-silicate mineral usually found in intrusive agpasitic igneous rocks. Yellow, reddish brown, Vitreous, Pearly.


  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. 1 2 "Tinaksite Mineral Data".
  3. 1 2 "Tinaksite".
  4. Mineralienatlas
  5. "TINAKSITE (Potasium Sodium Calcium Manganese Titanium Iron Oxide Silicate Hydroxide)".