Loparite-(Ce) | |
---|---|
General | |
Category | Oxide minerals |
Formula (repeating unit) | (Ce,Na,Ca)(Ti,Nb)O3 |
IMA symbol | Lop-Ce [1] |
Strunz classification | 4.CC.35 |
Crystal system | Loparit-(Ce)-Q: tetragonal [2] Loparit-(Ce)-O: orthorhombisch [2] Loparit-(Ce)-C: cubic [3] |
Identification | |
Color | Black to grey-brown in thin section |
Crystal habit | Cubic and octahedral crystals and massive |
Twinning | Penetration twins common on [111] |
Cleavage | [100] Imperfect |
Fracture | Uneven |
Tenacity | Brittle |
Mohs scale hardness | 5.5–6.0 |
Luster | Metallic to sub-metallic |
Streak | Reddish brown |
Diaphaneity | opaque, transparent in thin fragments |
Specific gravity | 4.60–4.89 |
Optical properties | Isotropic, anomalously anisotropic |
Refractive index | n = 2.26–2.38 |
References | [4] |
Loparite-(Ce) is a granular, brittle oxide mineral of the perovskite class. It is black to dark grey and may appear grey to white in reflected light on polished thin section with reddish brown internal reflections. [5] It has the chemical formula of (Ce,Na,Ca)(Ti,Nb)O3. [4] Nioboloparite is a variation of loparite-(Ce) containing niobium. [6]
Loparite occurs as a primary phase in nepheline syenite intrusions and pegmatites. It is also found replacing perovskite in carbonatites. [4]
Loparite was first described for an occurrence in the Khibiny and Lovozero massifs, Kola peninsula in northern Russia.
The term originates from the word Lopar, the (former) Russian name for the Sami indigenous inhabitants of the Kola peninsula, and the cerium content. [4] [5] [6]
Kogarkoite is a sodium sulfate fluoride mineral with formula Na3(SO4)F. It has a pale blue color, a specific gravity of about 2.67 and a hardness of 3.5. The crystal is monoclinic and is a type of naturally occurring antiperovskite. Kogarkoite is named after the Russian petrologist Lia Nikolaevna Kogarko (born 1936) who discovered the mineral.
Kassite is a rare mineral whose chemical formula is CaTi2O4(OH)2. It crystallizes in the orthorhombic crystal system and forms radiating rosettes and pseudo-hexagonal tabular crystals which are commonly twinned. Kassite crystals are brownish pink to pale yellow in color, are translucent, and have an adamantine luster. Cleavage is distinctly visible, and the crystals are very brittle.
Periclase is a magnesium mineral that occurs naturally in contact metamorphic rocks and is a major component of most basic refractory bricks. It is a cubic form of magnesium oxide (MgO). In nature it usually forms a solid solution with wüstite (FeO) and is then referred to as ferropericlase or magnesiowüstite.
Arfvedsonite is a sodium amphibole mineral with composition: [Na][Na2][(Fe2+)4Fe3+][(OH)2|Si8O22]. It crystallizes in the monoclinic prismatic crystal system and typically occurs as greenish black to bluish grey fibrous to radiating or stellate prisms.
Cerite is a complex silicate mineral group containing cerium, formula (Ce,La,Ca)
9(Mg,Fe3+
)(SiO
4)
6(SiO
3OH)(OH)
3. The cerium and lanthanum content varies with the Ce rich species and the La rich species. Analysis of a sample from the Mountain Pass carbonatite gave 35.05% Ce
2O
3 and 30.04% La
2O
3.
Fluorcaphite is a mineral with the chemical formula (Ca,Sr,Ce,Na)5(PO4)3F. It is found in the Kola Peninsula in Russia. Its crystals are hexagonal and are transparent with a vitreous luster. It is light to bright yellow, leaves a white streak and is rated five on the Mohs Scale. Fluorcaphite is radioactive.
Kukharenkoite-(Ce) is a barium cerium fluoride carbonate mineral, formula Ba2CeF(CO3)3. It was identified from samples found in the Mont-Saint-Hilaire alkaline intrusive complex, Quebec, and the Khibiny Massif, Kola peninsula, Russia. It was named for Russian mineralogist Alexander A. Kukharenko (1914–1993).
Nyerereite is a very rare sodium calcium carbonate mineral with formula Na2Ca(CO3)2. It forms colorless, platey pseudohexagonal orthorhombic crystals that are typically twinned. It has a specific gravity of 2.54 and indices of refraction of nα=1.511, nβ=1.533 and nγ=1.535. Nyerereite is not stable in contact with the atmosphere and rapidly breaks down. Collection specimens must be kept in a sealed argon environment.
Mckelveyite-(Y) is a hydrated sodium, barium, yttrium, and uranium–containing carbonate mineral, with the chemical formula Ba3Na(Ca,U)Y(CO3)6·3H2O.
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.
Cafetite is a rare titanium oxide mineral with formula (Ca,Mg)(Fe,Al)
2Ti
4O
12·4(H
2O). It is named for its composition, Ca-Fe-Ti.
Arctite (Na2Ca4(PO4)3F) is a colourless mineral found in the Kola Peninsula northern Russia. Its IMA symbol is Arc. It has a Mohs hardness of 5 and has a specific gravity of 3.13. Arctite is transparent with a vitreous lustre. Arctite has a perfect cleavage and a trigonal crystal system. It is also a naturally occurring antiperovskite.
Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula CaTiO3). Its name is also applied to the class of compounds which have the same type of crystal structure as CaTiO3, known as the perovskite structure, which has a general chemical formula A2+B4+(X2−)3. Many different cations can be embedded in this structure, allowing the development of diverse engineered materials.
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).
Banalsite is a rare barium, sodium aluminium silicate mineral with formula: BaNa2Al4Si4O16. Banalsite is a tectosilicate of the feldspar group.
Zorite is a silicate mineral with the chemical formula of Na2Ti(Si,Al)3O9·nH2O. It is named because of its pink color, after the Russian word "zoria" which refers to the rosy hue of the sky at dawn. It is primarily found in Mount Karnasurta, Lovozero Massif, Kola Peninsula, Russia. The Lovozero Massif is an area with an igneous mountain range, home to various types of minerals such as eudialyte, loparite, and natrosilitite.
Loveringite is a rare metallic oxide mineral of the crichtonite group with the chemical formula (Ca,Ce)(Ti,Fe,Cr,Mg)21O38. It is a late-stage magmatic mineral, formed in the residual melt of mafic layered intrusions in either the olivine-chromite, pyroxene, or plagioclase-rich layers.
Djerfisherite is an alkali copper–iron sulfide mineral and a member of the djerfisherite group.
Kovdorskite, Mg2PO4(OH)·3H2O, is a rare, hydrated, magnesium phosphate mineral. It was first described by Kapustin et al., and is found only in the Kovdor Massif near Kovdor, Kola Peninsula, Russia. It is associated with collinsite, magnesite, dolomite, hydrotalcite, apatite, magnetite, and forsterite.
Anzaite-(Ce) is a rare-earth element (REE) oxide mineral with the formula Ce4Fe2+Ti6O18(OH)2. An example of chemically related mineral is lucasite-(Ce), although it contains no iron. Cerium in anzaite-(Ce) is mainly substituted by neodymium, lanthanum, calcium and praseodymium. Titanium is substituted by niobium. Trace elements include thorium. The mineral is monoclinic, space group C2/m. Anzaite-(Ce) is hydrothermal mineral found in a carbonatite from the mineralogically prolific Kola Peninsula. The mineral name honors Anatoly N. Zaitsev, who is known for studies of carbonatites and REE.