Hexamolybdenum
| Hexamolybdenum | |
|---|---|
| General | |
| Category | Native mineral alloy |
| Formula (repeating unit) | (Mo,Ru,Fe,Ir,Os) |
| IMA symbol | Hmo[1] |
| Strunz classification | 1.XX.00 |
| Crystal system | Hexagonal |
| Crystal class | Dihexagonal dipyramidal (6/mmm) H-M symbol: (6/m 2/m 2/m) |
| Space group | P63/mmc |
| Unit cell | a = 2.7506, c = 4.4318 [Å] V = 29.04 Å3, Z = 2 |
| Identification | |
| Crystal habit | Inclusions and microscopic crystals |
| Specific gravity | 11.90 (calculated) |
| References | [2][3][4] |
Hexamolybdenum is a molybdenum dominant alloy discovered during a nanomineralogy investigation of the Allende meteorite.[4] Hexamolybdenum was discovered in a small ultrarefractory inclusion within the Allende meteorite.[4] This inclusion has been named ACM-1.[4] Hexamolybdenum is hexagonal, with a calculated density of 11.90 g/cm3.[4] The new mineral was found along with allendeite.[4] These minerals, are believed to demonstrate conditions during the early stages of the Solar System, as is the case with many CV3 carbonaceous chondrites such as the Allende meteorite.[4] Hexamolybdenum lies on a continuum of high-temperature alloys that are found in meteorites and allows a link between osmium, ruthenium, and iron rich meteoritic alloys.[4] The name hexamolybdenum refers to the crystal symmetry (primitive hexagonal) and the molybdenum rich composition.[4] The Allende meteorite fell in 1969 near Pueblito de Allende, Chihuahua, Mexico.[4]
Occurrence
[edit]Hexamolybdenum was found as nano-crystals in an ultrarefractory inclusion in the Allende meteorite.[4] The Allende meteorite has shown to be full of new minerals, after nearly forty years it has produced one in ten of the now known minerals in meteorites.[4] This CV3 carbonaceous chondrite was the largest ever recovered on earth and is referred to as the best-studied meteorite in history.[4] The inclusion has only been viewed via electron microscopy.[4] The hexamolybdenum specimen was lost during an attempted ion probe analysis of a bordering grain.[4] Other specimens can be found, however, in the Smithsonian Institution's National Museum of Natural History Allende section USNM 3509HC12 and in section USNM 7590 of NWA 1934, another VC3 chondrite.[4]
It has also been reported from the NWA 1934 CV3 carbonaceous chondrite meteorite from the Erfoud region of Morocco and in the Danubian placer of Straubing, Bavaria.[2]
Chemical composition
[edit]Hexamolybdenum is an (molybdenum, ruthenium, iron, iridium, osmium) alloy.[4]
Appearance
[edit]Color, streak, luster, hardness, tenacity, cleavage, fracture, density, and refractive index could not be observed because the grain size was too small and the section bearing the mineral was optically thick.[4]
See also
[edit]
References
[edit]- ^ 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.
- ^ a b Mindat.org
- ^ Webmineral data
- ^ a b c d e f g h i j k l m n o p q r Beckett, John R.; Rossman, George R. (2014). "Allendeite (Sc3Zr4O12 and hexamolybdenum (Mo, Ru, Fe), two new minerals from an ultrarefractory inclusion from the Allende meteorite". American Mineralogist. 99 (4): 654–666. Bibcode:2014AmMin..99..654M. doi:10.2138/am.2014.4667. S2CID 94914236.