Aleutite | |
---|---|
General | |
Category | vanadate and arsenate |
Formula (repeating unit) | [Cu5O2](AsO4)(VO4) · (Cu0.5□0.5)Cl |
IMA symbol | Aeu [1] |
Strunz classification | 4/K.01-10 |
Crystal system | Monoclinic |
Crystal class | 2/m - Prismatic |
Space group | C2/m |
Unit cell | a = 18.090(2) Å, b = 6.2248(6) Å; c = 8.2465(9) Å; β= 90.597(2)°; Z = 4 |
Identification | |
Formula mass | 287.26 |
Color | Dark red |
Cleavage | none observed |
Fracture | Irregular/Uneven |
Tenacity | Brittle |
Luster | Adamantine |
Streak | Reddish black |
Diaphaneity | Transparent |
Density | 4.887 g/cm3 |
References | [2] [3] [4] |
Aleutite is both a vanadate and arsenate mineral but it can also be considered as a natural salt-inclusion phase that was first discovered at Second scoria cone of the Great Fissure Tolbachik eruption in the summer of 2015 in Kamchatka, Russia. Aleutite is a fumarolic mineral found with many other newly discovered minerals at this location. It gained the name from the Aleuts, the ethnic group who are the original inhabitants living on the Commander Islands, Aleutsky District, Kamchatka Krai. This mineral is very brittle and has a dark red color. Aleutite is a new structure type, the structure was refined as a 2-component twin, the twin ratio equals (0.955:0.045). [2]
Aleutite occurs as a product of fumarolic activity. It was found in the summer of 2015 in Yadovitaya fumarole at the Second Scoria Cone of the Northern Breakthrough of the Great Fissure Tolbachik Eruption in Kamchatka, Russia. The Second Scoria Cone is located approximately 18 km SSW of the active shield volcano Ploskiy Tolbachik. The temperature of gases at the sampling location was about 300ºC. Aleutite could be deposited directly from the gas phase as a volcanic sublimate. All the recovered samples were immediately packed and isolated to avoid any contact with atmosphere. Aleutite is very rare and closely associates with anhydrite. Other associated minerals are euchlorine, kamchatkite, langbeinite, lyonsite, pseudolyonsite, tenorite, hematite. [2]
Aleutite occurs as individual crystals in the masses of polycrystalline anhydrite. Aleutite is dark red, with reddish black streak, and has an adamantine luster. It is brittle with no visible cleavage observed. Parting was not observed, and its fracture is uneven. The density could not be measured due to lack of sufficient material. The calculated specific gravity is 4.887 g/cm3. [2]
The measured optical properties of Aleutite were found through reflected light. The mineral had high values of refractive indices which is typical of arsenates and vanadates. Reflectance measurements were made using a SiC standard in air which ranged from 400–700 nm. Aleutite is grey with yellowish tint in reflected light, it is non-pleochroic with abundant brown-red internal reflections and a weak bireflectance. [2]
Aleutite is both a vanadate and arsenate that may can compared to averievite which has had a formula of Cu6(VO4)2O2Cl2. It may also be comparable with piypite with a formula of K2Cu2O(SO4)2. [3] The empirical formula of Aleutite cab be calculated on the basis of (As+V+Mo+Fe3+) = 2 apfu is Сu5.40Zn0.05Ca0.01As1.09V0.84Mo0.04Fe0.03K0.05Pb0.02Rb0.01Cs0.01O9.97Cl1.07 or (Сu4.94Zn0.05Ca0.01)Σ5.00O2.11[(As2.11V0.42Mo0.02Fe0.02)Σ1.00OΣ3.93]2 ∙ (Cu0.46K0.05Pb0.02Rb0.01Cs0.01)Σ0.55Cl1.07. Taking into account structural data, the simplified formula is [Cu5O2](AsO4)(VO4)·(Cu0.5□0.5)Cl. Aleutite is soluble in hot H2O. [2]
Constituent | wt% | Range |
---|---|---|
MoO3 | 0.83 | 0.62 – 1.02 |
As2O5 | 18.33 | 17.77 – 19.83 |
V2O5 | 11.13 | 10.56 – 11.85 |
Fe2O3 | 0.36 | 10.56 – 11.85 |
CuO | 62.73 | 61.79 – 63.54 |
ZnO | 0.60 | 0.39 – 0.77 |
PbO | 0.75 | 0.59 – 0.98 |
CaO | 0.10 | 0.00 – 0.22 |
K2O | 0.35 | 0.24 – 0.47 |
Cs2O | 0.16 | 0.05 – 0.31 |
Rb2O | 0.18 | 0.09 – 0.27 |
Cl | 5.54 | 5.40 – 5.78 |
-Cl=O | 1.25 | |
Total | 99.81 | 100.02 – 101.83 |
Aleutite is in the monoclinic crystal system and has a space group of C2/m. [2] Its unit cell dimensions are as follows: a = 18.0788(9) Å, b = 6.2270(5) Å, c = 8.2445(3) Å, β = 90.56(4)º, V = 928.09(7) Å3, Z = 4. Aleutite has a point group of 2/m. [3] The [Cu5O2]6+ band in aleutite can be considered part of a kagome network. [4]
Vanadinite is a mineral belonging to the apatite group of phosphates, with the chemical formula Pb5(VO4)3Cl. It is one of the main industrial ores of the metal vanadium and a minor source of lead. A dense, brittle mineral, it is usually found in the form of red hexagonal crystals. It is an uncommon mineral, formed by the oxidation of lead ore deposits such as galena. First discovered in 1801 in Mexico, vanadinite deposits have since been unearthed in South America, Europe, Africa, and North America.
Carnotite is a potassium uranium vanadate radioactive mineral with chemical formula K2(UO2)2(VO4)2·3H2O. The water content can vary and small amounts of calcium, barium, magnesium, iron, and sodium are often present.
Tokyoite is a rare barium manganese vanadate mineral with the chemical formula: Ba2(Mn3+,Fe3+)OH(VO4)2. It is the manganese analogue of the iron rich gamagarite and the barium analogue of the lead vanadate, brackebuschite.
Alarsite (AlAsO4) is an aluminium arsenate mineral with its name derived from its composition: aluminium and arsenate. It occurs as brittle subhedral grains which exhibit trigonal symmetry. It has a Mohs hardness of 5-5.5 and a specific gravity of 3.32. It is semitransparent, colorless with pale yellow tints and shows a vitreous luster. It is optically uniaxial (+) with refractive indices of nω = 1.596 and nε = 1.608.
Blossite is an anhydrous copper vanadate mineral with the formula: Cu2+V5+2O7. Blossite was named for mineralogist F. Donald Bloss of Virginia Polytechnic Institute and State University.
Tangeite, also known as calciovolborthite, is a calcium, copper vanadate mineral with formula: CaCu(VO4)(OH). It occurs as a secondary mineral that can be found in sandstone and also in the oxidized zones of vanadium bearing deposits.
Urusovite is a rare copper aluminium arsenate mineral with formula: CuAlAsO5. It is a monoclinic-prismatic light green mineral.
Gurimite is a rare mineral with formula Ba3(VO4)2. It is a simple barium vanadate, one of the most simple barium minerals known. It is named after its type locality - Gurim anticline in Israel. It has formed in the rocks of the Hatrurim Formation. Gurimite's stoichiometry is similar to that of copper vanadates mcbirneyite and pseudolyonsite. An example of other barium vanadate mineral is tokyoite.
Feodosiyite is a very rare chloride mineral, just recently approved, with the formula Cu11Mg2Cl18(OH)8•16H2O. Its structure is unique. Feodosiyite comes from the Tolbachik volcano, famous for many rare fumarolic minerals. Chemically similar minerals, chlorides containing both copper and magnesium, include haydeeite, paratacamite-(Mg) and tondiite.
Vasilseverginite is a very rare arsenate-sulfate mineral with formula Cu9O4(AsO4)2(SO4)2. Its structure is of a new type. It possesses a typical feature of many minerals of its type locality, the Tolbachik volcano, namely being a salt with oxide anions. However, it is the first Tolbachik copper oxysalt that is both arsenate and sulfate. Vasilseverginite is monoclinic, with space group P21/n.
Chrysothallite is a rare thallium-bearing chloride mineral with the formula K6Cu6Tl3+Cl17(OH)4•H2O. Chrysothallite is unique in being only the second mineral with essential trivalent thallium, a feature shared with natural thallium(III) oxide, avicennite. Another examples of natural thallium chlorides are steropesite, Tl3BiCl6, and lafossaite, TlCl. Chrysothallite is one of numerous fumarolic minerals discovered among fumarolic sites of the Tolbachik volcano, Kamchatka, Russia The mineral is named in allusion to its colour and thallium content.
Itelmenite is a rare sulfate mineral with the formula Na4Mg3Cu3(SO4)8. It is one of many fumarolic minerals discovered on the Tolbachik volcano.
Hermannjahnite is a rare sulfate mineral with the relatively simple formula CuZn(SO4)2. It is one of many fumarolic minerals discovered on the Tolbachik volcano.
Kainotropite is a rare vanadate mineral with the formula Cu4FeO2(V2O7)(VO4). It contains trivalent iron. It is one of many fumarolic minerals discovered on the Tolbachik volcano. The name of its parental fumarole is "Yadovitaya", which means poisonous.
Gottlobite, CaMg(VO4,AsO4)(OH), is a mineral found as isolated crystals or isometric grains of orange or orange-brown color. The size of the crystals are a half millimeter in diameter and are part of the orthorhombic crystal system. Gottlobite forms a solid solution with adelite, which is an end member composition of CaMg(VO4)(OH), as well as being classified in the adelite group. Gottlobite is also part of the vanadates and arsenates group. With these characteristics, it is similar to the minerals tangeite and austinite by X-ray diffraction methods.
Sengierite is a rare oxide and hydroxide mineral, chemically a copper and uranyl vanadate, belonging to the carnotite group. Its chemical formula is Cu2(OH)2[UO2|VO4]2·6H2O.
Wulffite is an alkali copper sulfate mineral with the chemical formula K3NaCu4O2(SO4)4, in the sulfate category of minerals. It was recently discovered in Kamchatka, Russia at the Tolbachik volcano in 2012. It was named for Russian crystallographer Georgiy Viktorovich Wulff, a renowned expert who furthered X-ray diffraction and interference. Wullfite shares many properties with parawulffite, which was found in the same area just with slightly different chemical composition.
Euchlorine (KNaCu3(SO4)3O) is a rare emerald-green colored sulfate mineral found naturally occurring as a sublimate in fumaroles around volcanic eruptions. It was first discovered in fumaroles of the 1868 eruption at Mount Vesuvius in Campania, Italy by Arcangelo Scacchi. The name 'euchlorine' comes from the Greek word εΰχλωρος meaning "pale green" in reference to the mineral's color, other reported spellings include euclorina, euchlorin, and euchlorite.
Fumarole minerals are minerals which are deposited by fumarole exhalations. They form when gases and compounds desublimate or precipitate out of condensates, forming mineral deposits. They are mostly associated with volcanoes following deposition from volcanic gas during an eruption or discharge from a volcanic vent or fumarole, but have been encountered on burning coal deposits as well. They can be black or multicoloured and are often unstable upon exposure to the atmosphere.
Petrovite is a blue and green mineral, with the chemical formula of Na10CaCu2(SO4)8. It contains atoms of oxygen (O), sodium (Na), sulphur (S), calcium (Ca) and copper (Cu) in a porous framework. It has potential as a cathode material in sodium-ion rechargeable batteries.