Gilbertite

Where it forms, where it's found

38recorded occurrences

Source · OpenStreetMap

Optical

UV response: Not fluorescent in UV

Chemical composition

Constituent elements: Mass composition breakdown
Element Atoms At. mass g/mol Mass g/mol Mass share
8OOxygen Oxygen 12 15.999 191.988
48.20%
14SiSilicon Silicon 3 28.085 84.255
21.15%
13AlAluminium Aluminium 3 26.982 80.946
20.32%
19KPotassium Potassium 1 39.098 39.098
9.82%
1HHydrogen Hydrogen 2 1.008 2.016
0.51%
Total 398.303 100.00%
Mass share = atoms × atomic mass ÷ molar mass × 100
From Mindat formula

Mass composition breakdown
Element	Atoms	At. mass g/mol	Mass g/mol	Mass share
8OOxygen	Oxygen	12	15.999	191.988	48.20%
14SiSilicon	Silicon	3	28.085	84.255	21.15%
13AlAluminium	Aluminium	3	26.982	80.946	20.32%
19KPotassium	Potassium	1	39.098	39.098	9.82%
1HHydrogen	Hydrogen	2	1.008	2.016	0.51%
	Total	398.303	100.00%

Synonyms

Gilbertit
Gilbertita

Literature, links & citation

Citations

1831Thomson, T. (1831) Transactions of the Royal Society of Edinburgh, 11, 383 [Hey3].

Cite this entry

@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Gilbertite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/gilbertite-1692},
  note      = {Accessed 2026-05-11}
}