Pleonaste

Where it forms, where it's found

98recorded occurrences

Source · OpenStreetMap

Chemical composition

Constituent elements: Mass composition breakdown
Element Atoms At. mass g/mol Mass g/mol Mass share
8OOxygen Oxygen 4 15.999 63.996
32.30%
26FeIron Iron 1 55.845 55.845
28.19%
13AlAluminium Aluminium 2 26.982 53.964
27.24%
12MgMagnesium Magnesium 1 24.305 24.305
12.27%
Total 198.110 100.00%
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	4	15.999	63.996	32.30%
26FeIron	Iron	1	55.845	55.845	28.19%
13AlAluminium	Aluminium	2	26.982	53.964	27.24%
12MgMagnesium	Magnesium	1	24.305	24.305	12.27%
	Total	198.110	100.00%

Synonyms

Pleonast

Literature, links & citation

Citations

1801Haüy (1801).
1944Palache, Charles, Berman, Harry, Frondel, Clifford (1944) The System of Mineralogy (7th ed.) Vol. 1 - Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, New York.

Cite this entry

@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Pleonaste — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/pleonaste-6684},
  note      = {Accessed 2026-05-11}
}