Stillwellite-(La)

LaBSiO5
IMA status
  • Approved
  • Pending publication
IMA symbol
Swl-La
Also known as
  • IMA2024-074
  • Stillwelliet-(La)

Where it forms, where it's found

Type locality
Gejiu intrusion
  1. Gejiu City
  2. Honghe
  3. Yunnan
  4. China

23.4944°, 103.0781°

1recorded occurrences
Source · OpenStreetMap

Crystallography

Crystal system
Trigonal
Space group
P32 2 1
Cell parameters
a = 6.9061(5) Å · c = 6.7549(5) Å
Crystal structure

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
57LaLanthanumLanthanum1138.905138.905
53.88%
8OOxygenOxygen515.99979.995
31.03%
14SiSiliconSilicon128.08528.085
10.90%
5BBoronBoron110.81010.810
4.19%
Total257.795100.00%

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

From Mindat formula

Synonyms

  • IMA2024-074
  • Stillwelliet-(La)

In other languages

German
IMA 2024-074 · Stillwellit-(La)

Classification

Strunz
10th ed.

9.AJ.25

  • 9SilicatesClass
  • 9.ANesosilicatesDivision
  • 9.AJNesosilicates with BO3 triangles and/or B[4], Be[4] tetrahedra, cornersharing with SiO4Group
  • 9.AJ.25Stillwellite-(La)Species

Literature, links & citation

Citations
  1. 2025Bosi, Ferdinando; Hatert, Frédéric; Pasero, Marco; Mills, Stuart J. (2025) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) – Newsletter 84. European Journal of Mineralogy, 37 (2). 249-255 doi:10.5194/ejm-37-249-2025 DOI: 10.5194/ejm-37-249-2025
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Stillwellite-(La) — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/stillwellite-la-471947},
  note      = {Accessed 2026-05-11}
}