Trilithionite

KLi1.5Al1.5(Si3Al)O10F2
IMA status
  • Approved
IMA symbol
Tln
Also known as
  • Trilithioniet

Where it forms, where it's found

38recorded occurrences
Source · OpenStreetMap

Physical

Colour
Pink-violet

Crystallography

Crystal system
Monoclinic
Space group
C2/c
Cell parameters
a = 9.056 Å · b = 5.216 Å · c = 20.282 Å
Cell angles
β = 99.64 °
Ratio a:b:c
1 : 0.576 : 2.240
Comment

Data from Brigatti et al. (2005) (sample from Chedeville, France; polytype 2M2)

Crystal structure

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
8OOxygenOxygen1015.999159.990
40.08%
14SiSiliconSilicon328.08584.255
21.10%
13AlAluminiumAluminium2.526.98267.455
16.90%
19KPotassiumPotassium139.09839.098
9.79%
9FFluorineFluorine218.99837.996
9.52%
3LiLithiumLithium1.56.94010.410
2.61%
Total399.204100.00%

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

From IMA formula

Synonyms

  • Trilithioniet

In other languages

German
Trilithionit
Italian
trilitionite

Classification

Strunz
10th ed.

9.EC.20

  • 9SilicatesClass
  • 9.EPhyllosilicatesDivision
  • 9.ECPhyllosilicates with mica sheets, composed of tetrahedral and octahedral netsGroup
  • 9.EC.20TrilithioniteSpecies

Group, growth & confusion

In the same group
3 members

Literature, links & citation

Citations
  1. 1998Rieder, M., Cavazzini, G., D’Yakonov, Y.S., Frank-Kamenetskii, V.A., Gottardt, G., Guggenheim, S., Koval, P.V., Muller, G., Neiva, A.M.R., Radoslovich, E.W., Robert, J.L., Sassi, F.P., Takeda, H., Weiss, Z., Wones, D.R. (1998) Nomenclature of the micas. The Canadian Mineralogist, 36 (3) 905-912
  2. 2005Brigatti, M. F., Caprilli, E., Malferrari, D., Medici, L., Poppi, L. (2005) Crystal structure and chemistry of trilithionite-2M2 and polylithionite-2M2. European Journal of Mineralogy: 17(3): 475-481.
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Trilithionite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/trilithionite-7341},
  note      = {Accessed 2026-05-11}
}