Riesite

TiO2
IMA status
  • Approved
IMA symbol
Rie
IMA approved
2016
Also known as
  • IMA2015-110a
  • Riesiet

Where it forms, where it's found

Geological setting

Impact crater in xenolith of garnet-sillimanite restite with shock-melt veins that was trapped in suevite.

Type locality
Zipplinger Höhe
  1. Zipplingen
  2. Unterschneidheim
  3. Ostalbkreis
  4. Stuttgart Region
  5. Baden-Württemberg
  6. Germany

48.9265°, 10.4089°

1recorded occurrences
Source · OpenStreetMap

Physical

Transparency
Opaque
Density
4.37 g/cm³

Crystallography

Crystal system
Monoclinic
Space group
P1 2/c 1
Cell parameters
a = 4.519(3) Å · b = 5.503(8) Å · c = 4.888(2) Å
Cell angles
β = 90.59(8) °
Ratio a:b:c
1 : 1.218 : 1.082

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
22TiTitaniumTitanium147.86747.867
59.93%
8OOxygenOxygen215.99931.998
40.07%
Total79.865100.00%

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

From IMA formula

Synonyms

  • IMA2015-110a
  • Riesiet

In other languages

German
IMA 2015-110a · Riesit

Classification

Strunz
10th ed.

4.DM.45

  • 4OxidesClass
  • 4.DMetal: Oxygen = 1:2 and similarDivision
  • 4.DMWith large (+- medium-sized) cations; unclassifiedGroup
  • 4.DM.45RiesiteSpecies

Group, growth & confusion

Commonly confused with
4 minerals

Literature, links & citation

Citations
  1. 2017Hålenius, Ulf, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2017) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 35. European Journal of Mineralogy, 29 (1) 149-152 doi:10.1127/ejm/2017/0029-2626DOI: 10.1127/ejm/2017/0029-2626
  2. 2020Tschauner, Oliver, Ma, Chi, Lanzirotti, Antonio, Newville, Matthew G. (2020) Riesite, a New High Pressure Polymorph of TiO2 from the Ries Impact Structure. Minerals, 10 (1) 78 doi:10.3390/min10010078 DOI: 10.3390/min10010078
  3. 2021(2021) Riesite. Handbook of Mineralogy. Mineralogical Society of America
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Riesite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/riesite-51474},
  note      = {Accessed 2026-05-11}
}