Machiite

Al2Ti3O9
IMA status
  • Approved
IMA symbol
Mci
IMA approved
2016
Also known as
  • IMA2016-067
  • Machiiet

Where it forms, where it's found

Type locality
Murchison meteorite
  1. Murchison
  2. City of Greater Shepparton
  3. Victoria
  4. Australia

-36.6167°, 145.2000°

3recorded occurrences
Source · OpenStreetMap

Physical

Density
4.27 g/cm³

Crystallography

Crystal system
Monoclinic
Space group
C2/c
Cell parameters
a = 17.102 Å · b = 5.025 Å · c = 7.058 Å
Cell angles
β = 106.6 °
Ratio a:b:c
1 : 0.294 : 0.413
Unit cell volume
581 ų
Z
4
Type-locality form

A single euhedral crystal, 4.4 um in size, in contact with an euhedral corundum grain, 12 um in size.

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
8OOxygenOxygen915.999143.991
42.16%
22TiTitaniumTitanium347.867143.601
42.04%
13AlAluminiumAluminium226.98253.964
15.80%
Total341.556100.00%

Mass share = atoms × atomic mass ÷ molar mass × 100

From IMA formula

Synonyms

  • IMA2016-067
  • Machiiet

In other languages

German
IMA 2016-067 · Machiit

Classification

Strunz
10th ed.

4.CB.35

  • 4OxidesClass
  • 4.CMetal: Oxygen = 2: 3,3: 5, and similarDivision
  • 4.CBWith medium-sized cationsGroup
  • 4.CB.35MachiiteSpecies

Group, growth & confusion

Commonly confused with
1 mineral

Literature, links & citation

Citations
  1. 2016(2016)
  2. 2016Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2016) New minerals and nomenclature modifications approved in 2016, CNMNC Newsletter No 34. Mineralogical Magazine, 80 (7) 1315-1321 doi:10.1180/minmag.2016.080.086DOI: 10.1180/minmag.2016.080.086
  3. 2017(2017)
  4. 2020(2020) Machiite. Handbook of Mineralogy. Mineralogical Society of America
  5. 2020Krot, 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-2020-7185DOI: 10.2138/am-2020-7185
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Machiite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/machiite-50775},
  note      = {Accessed 2026-05-11}
}