Bastinite

(Mn,Fe)5(PO4)2(PO3OH)2·4H2O
Also known as
  • Bastinit
  • Bastinita

Where it forms, where it's found

Geological setting

Late stage phosphate alteration in granite pegmatites.

Type locality
Custer Mountain lode (Snookum mine)
  1. Custer
  2. Custer Mining District
  3. Custer County
  4. South Dakota
  5. USA

43.7548°, -103.5662°

4recorded occurrences
Source · OpenStreetMap

Physical

Hardness
123456789104/ 10 MOHS
  1. 1Talc
  2. 2Gypsum
  3. 3Calcite
  4. 4Fluorite
  5. 5Apatite
  6. 6Orthoclase
  7. 7Quartz
  8. 8Topaz
  9. 9Corundum
  10. 10Diamond
Transparency
Transparent
Colour
Light pink to colorless
Streak
White
Tenacity
brittle

Optical

UV response
Not fluorescent

Crystallography

Type-locality form

platy light pink crystals, 1 mm or less

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
8OOxygenOxygen2015.999319.980
31.75%
26FeIronIron555.845279.225
27.70%
25MnManganeseManganese554.938274.690
27.26%
15PPhosphorusPhosphorus430.974123.896
12.29%
1HHydrogenHydrogen101.00810.080
1.00%
Total1007.871100.00%

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

From Mindat formula

Synonyms

  • Bastinit
  • Bastinita

Literature, links & citation

Citations
  1. Fisher, D. Jerome (1946): Bastinite, a new pegmatite phosphate. American Mineralogist, 31: 192.
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Bastinite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/bastinite-559},
  note      = {Accessed 2026-05-11}
}