Where it forms, where it's found
- Geological setting
Telethermal deposit consisting of a single selenide vein hosted in sandstones and shales.
- Type locality
- El Dragón mine
- Porco Municipality
- Antonio Quijarro Province
- Potosí
- Bolivia
-19.8208°, -65.9167°
1recorded occurrences
Safety & handling
Physical
- Hardness
- 1Talc
- 2Gypsum
- 3Calcite
- 4Fluorite
- 5Apatite
- 6Orthoclase
- 7Quartz
- 8Topaz
- 9Corundum
- 10Diamond
- Transparency
- Transparent
- Colour
- Blue
- Streak
- Very pale blue
- Tenacity
- brittle
- Cleavage
- None Observed
Cleavage could not be determined due to the small crystal size. By its structural analogue to linarite, it should have perfect cleavage on (100).
- Density
- 5.64 g/cm³
Optical
- Notes
No optical data were measured due to the intergrowth with anglesite.
Crystallography
- Space group
- P21/m
- Cell parameters
- a = 9.8208(3) Å · b = 5.7340(2) Å · c = 4.7498(1) Å
- Cell angles
- β = 102.683(2) °
- Ratio a:b:c
- 1 : 0.584 : 0.484
- Z
- 2
- Type-locality form
Prismatic crystals included in colourless anglesite. Individual crystals of franksousaite are found up to 0.05 × 0.02 × 0.02 mm.
Chemical composition
Synonyms
- Franksousaiet
- IMA2021-096
In other languages
- German
- Franksousait · IMA 2021-096
Classification
Strunz
10th ed.7.BC.65
- 7SulfatesClass
- 7.BSulfates (selenates, etc.) with additional anions, without H2ODivision
- 7.BCWith medium-sized and large cationsGroup
- 7.BC.65FranksousaiteSpecies
Group, growth & confusion
Literature, links & citation
Citations
- 2022(2022) Franksousaite. Handbook of Mineralogy. Mineralogical Society of America
- 2022Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2022) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) – Newsletter 65. European Journal of Mineralogy, 34 (1) 143-148 doi:10.5194/ejm-34-143-2022 DOI: 10.5194/ejm-34-143-2022
- 2022Yang, Hexiong, McGlasson, James A., Gibbs, Ronald B., Downs, Robert T. (2022) Franksousaite, PbCu(Se6+O4)(OH)2, the Se6+ analogue of linarite, a new mineral from the El Dragón mine, Potosí, Bolivia. Mineralogical Magazine, 86 (5) 792-798 doi:10.1180/mgm.2022.90 DOI: 10.1180/mgm.2022.90
Cite this entry
@misc{mineral2026,
author = {Mineral Index editorial board},
title = {Franksousaite — Mineral Index},
year = {2026},
url = {https://mineralindex.org/minerals/franksousaite-55765},
note = {Accessed 2026-05-11}
}