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Machiite

A valid IMA mineral species
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Formula:
Al2Ti3O9
The more detailed formula is (Al,Sc)2(Ti,Zr)3O9.
Specific Gravity:
4.27 (Calculated)
Crystal System:
Monoclinic
Name:
In honour of Chi Ma, Director of the Geological and Planetary Sciences Division–Analytical Facility at the Caltech (California, USA), in recognition of his expertise in nano-scale mineralogy and discoverer of many new minerals.
Isostructural with:
Schreyerite
The Al analogue of schreyerite. The first purely Al-Ti oxide mineral. The more detailed formula is (Al,Sc)2(Ti,Zr)3O9.

Chemically, but not structurally, the Al analogue of pseudorutile.

Machiite is depleted in the 16O isotope as compared to closely associated corundum. It is supposed to be formed as a condensate of the solar nebula gas or crystallization of a refractory melt.


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Unique IdentifiersHide

Mindat ID:
50775
Long-form identifier:
mindat:1:1:50775:8

Similar NamesHide

MuchiteA synonym of 'Muckite'

IMA Classification of MachiiteHide

Classification of MachiiteHide

Strunz-mindat (2026):
4.CB.35

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
C : Metal: Oxygen = 2: 3,3: 5, and similar
B : With medium-sized cations

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
MciIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of MachiiteHide

Density:
4.27 g/cm3 (Calculated)

Chemistry of MachiiteHide

Mindat Formula:
Al2Ti3O9

The more detailed formula is (Al,Sc)2(Ti,Zr)3O9.
Element Weights:
Element% weight
O42.158 %
Ti42.043 %
Al15.799 %

Calculated from ideal end-member formula.
O
Ti
Al
Elements listed:
Al, O, Ti - search for minerals with similar chemistry

Crystallography of MachiiteHide

Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 17.102 Å, b = 5.025 Å, c = 7.058 Å
β = 106.6°
Ratio:
a:b:c = 3.403 : 1 : 1.405
Unit Cell V:
581 ų
Z:
4

X-Ray Powder DiffractionHide

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 1: Primary nebular phases4.567-4.561
3 : Solar nebular condensates (CAIs, AOAs, URIs)>4.565
Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere<0.6
50 : Coal and/or oil shale minerals<0.36
Stage 10b: Anthropogenic minerals<10 Ka
54 : Coal and other mine fire minerals (see also #51 and #56)

Type Occurrence of MachiiteHide

Type Locality:
ⓘ Murchison meteorite, Murchison, City of Greater Shepparton, Victoria, Australia
General Appearance of Type Material:
A single euhedral crystal, 4.4 um in size, in contact with an euhedral corundum grain, 12 um in size.
Place of Conservation of Type Material:
Meteorite collections of the Hawai’i Institute of Geophysics and Planetology, University of Hawai’i at Mānoa, 1680 East-West Road, Honolulu, Hawai’i 96822, USA, Murchison section UH80
Associated Minerals at Type Locality:
Corundum
Reference:
Krot, Alexander N., Nagashima, Kazuhide, Rossman, George R. (2020) Machiite, Al2Ti3O9, a new oxide mineral from the Murchison carbonaceous chondrite: A new ultra-refractory phase from the solar nebula. American Mineralogist, 105 (2). 239-243 doi:10.2138/am-2020-7185

Synonyms of MachiiteHide

Other Language Names for MachiiteHide

Dutch:Machiiet
German:Machiit

Related Minerals - Strunz-mindat GroupingHide

4.CB.Magnesiohögbomite-6N12SMg5Al11TiO23(OH)Trig. 3m(32/m) : R3m
4.CB.KidoditeBaMg2Fe16O27Hex. 6/mmm(6/m2/m2/m) : P63/mmc
4.CB.Ferrohögbomite-2N2S[(Fe2+,Mg,Zn,Al)3(Al,Ti,Fe3+)8O15(OH)]2Hex. 6mm : P63mc
4.CB.Zhenruite(MoO3)2 · H2OMon. 2/m : P21/m
4.CB.FuyuaniteMg7Nb6O18(OH)8Trig. 3 : P3
4.CB.VirgilluethiteMoO3 · H2OMon. 2/m : P21/c
4.CB.Pengite(Pb8Sb3+3)ÎŁ11Sb5+9O35Trig. 3m(32/m) : R3m
4.CB.05BrizziiteNaSb5+O3Trig. 3 : R3
4.CB.05TistariteTi3+2O3Trig. 3m(32/m) : R3c
4.CB.05HematiteFe2O3Trig. 3m(32/m) : R3c
4.CB.05EcandrewsiteZnTiO3Trig. 3 : R3
4.CB.05MelanostibiteMn2+2Fe3+Sb5+O6Trig. 3 : R3
4.CB.05'UM1998-11-O-AuHSb'Au+2Sb3+O2(OH)
4.CB.05KarelianiteV3+2O3Trig. 3m(32/m) : R3c
4.CB.05CorundumAl2O3Trig. 3m(32/m) : R3c
4.CB.05EskolaiteCr2O3Trig. 3m(32/m) : R3c
4.CB.05GeikieliteMgTiO3Trig. 3 : R3
4.CB.05AkimotoiteMgSiO3Trig. 3 : R3
4.CB.05'Unnamed (Fe-Cr Oxide)'FeCrO3Trig. 3 : R3
4.CB.05'Auroantimonate'AuSbO3
4.CB.05HemleyiteFe2+SiO3Trig. 3 : R3
4.CB.05IlmeniteFe2+TiO3Trig. 3 : R3
4.CB.05PyrophaniteMn2+TiO3Trig. 3 : R3
4.CB.10Bixbyite-(Fe)(Fe,Mn)2O3Iso.
4.CB.10Bixbyite-(Mn)Mn3+2O3Iso. m3(2/m3) : Ia3
4.CB.10AvicenniteTl3+2O3Iso. m3(2/m3) : Ia3
4.CB.15ArmalcoliteMgTi4+2O5Orth. mmm(2/m2/m2/m)
4.CB.15FerropseudobrookiteFe2+Ti4+2O5Orth. mmm(2/m2/m2/m) : Cmcm
4.CB.15GriffiniteAl2Ti4+O5Orth. mmm(2/m2/m2/m) : Cmcm
4.CB.15Pseudobrookite Group
4.CB.15SassiteTi3+2Ti4+O5Orth. mmm(2/m2/m2/m) : Cmcm
4.CB.15PseudobrookiteFe3+2Ti4+O5Orth. mmm(2/m2/m2/m) : Cmcm
4.CB.20Zincovelesite-6N6SZn3(Fe3+,Mn3+,Al,Ti)8O15(OH)Trig. 3m(32/m) : P3m1
4.CB.20Magnesiohögbomite-2N4S(Mg8.43Fe2+1.57)Σ=10Al22Ti4+2O46(OH)2Hex. 6mm : P63mc
4.CB.20Magnesiobeltrandoite-2N3S(Mg6Al2)(Al18Fe3+2)O38(OH)2 Trig. 3m : P3m1
4.CB.20Zincohögbomite-2N6S[(Zn,Mg)7(Al,Fe3+,Ti)16O31(OH)]2Hex. 6mm : P63mc
4.CB.20Magnesiohögbomite-6N6S[(Mg,Fe2+)3(Al,Ti,Fe3+)8O15(OH)]6Trig. 3m(32/m) : R3m
4.CB.20Magnesiohögbomite-2N3S[(Mg,Fe2+,Zn)4(Al,Ti,Fe3+)10O19(OH)]2Trig. 3m(32/m) : P31m
4.CB.20Magnesiohögbomite-2N2S[(Mg,Fe2+)3[Al7(Ti,Fe3+)]O15(OH)]2Hex. 6mm : P63mc
4.CB.20'Ferrohögbomite-6N12S'[(Fe2+,Mg,Zn)5(Al,Ti,Fe3+)12O23(OH)]6Trig. 3m(32/m) : R3m
4.CB.20Zincohögbomite-2N2S[(Zn,Al,Fe2+)3(Al,Fe3+,Ti)8O15(OH)]2Hex. 6mm : P63mc
4.CB.25KleberiteFeTi6O11(OH)5Mon. 2/m : P21/c
4.CB.25PseudorutileFe3+2Ti4+3O9Hex. 622 : P6322
4.CB.30OxyvaniteV3+2V4+O5Mon. 2/m : B2/b
4.CB.30BerdesinskiiteV3+2TiO5Mon.
4.CB.30KaitianiteTi3+2Ti4+O5Mon. 2/m : B2/b
4.CB.35Vestaite(Ti4+Fe2+)Ti4+3O9Mon. 2/m : B2/b
4.CB.35Olkhonskite(Cr,V)2Ti3O9Mon.
4.CB.35SchreyeriteV3+2Ti4+3O9Mon. 2/m : B2/b
4.CB.40Zincorinmanite-(Zn)Zn2Sb2(Fe3+4Zn2)O14(OH)2Hex. 6mm : P63mc
4.CB.40MajindeiteMg2Mo3O8Hex. 6mm : P63mc
4.CB.40AlmagreraiteCuZnMn4+3O8Orth. mm2 : Pmn21
4.CB.40KamiokiteFe2Mo3O8Hex. 6mm : P63mc
4.CB.40NolaniteV3+8Fe3+2O14(OH)2Hex. 6mm : P63mc
4.CB.40IseiteMn2Mo3O8Hex. 6mm : P63mc
4.CB.40RinmaniteZn2Sb2Mg2Fe4O14(OH)2Hex. 6 : P63
4.CB.45StibioclaudetiteAsSbO3Mon. 2/m : P21/m
4.CB.45ClaudetiteAs2O3Mon. 2/m : P21/c
4.CB.50SenarmontiteSb2O3Iso. m3m(4/m32/m) : Fd3m
4.CB.50ArsenoliteAs2O3Iso. m3m(4/m32/m) : Fd3m
4.CB.55ValentiniteSb2O3Orth. mmm(2/m2/m2/m) : Pccn
4.CB.60BismiteBi2O3Mon. 2/m : P21/c
4.CB.65SphaerobismoiteBi2O3Tet.
4.CB.70SilléniteBi12SiO20Iso. 23 : I23
4.CB.75KyzylkumiteV3+Ti2O5(OH)Mon. 2/m : P21/c
4.CB.80'Tietaiyangite'Fe3+4Fe2+TiO9Hex.
4.CB.85LiuiteFeTiO3Orth. mmm(2/m2/m2/m) : Pnma
4.CB.90LuogufengiteFe2O3Orth. mm2 : Pna21
4.CB.95WangdaodeiteFeTiO3Trig. 3m : R3c

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Internet Links for MachiiteHide

References for MachiiteHide