Ferrithorite

Where it forms, where it's found

10recorded occurrences

Source · OpenStreetMap

Radioactivity

Physical

Colour: Orange
Density: 4.96 g/cm³

Crystallography

Type-locality form: dense waxlike masses

Chemical composition

Constituent elements: Mass composition breakdown
Element Atoms At. mass g/mol Mass g/mol Mass share
90ThThorium Thorium 1 232.038 232.038
51.79%
8OOxygen Oxygen 8 15.999 127.992
28.57%
26FeIron Iron 1 55.845 55.845
12.47%
14SiSilicon Silicon 1 28.085 28.085
6.27%
1HHydrogen Hydrogen 4 1.008 4.032
0.90%
Total 447.992 100.00%
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
90ThThorium	Thorium	1	232.038	232.038	51.79%
8OOxygen	Oxygen	8	15.999	127.992	28.57%
26FeIron	Iron	1	55.845	55.845	12.47%
14SiSilicon	Silicon	1	28.085	28.085	6.27%
1HHydrogen	Hydrogen	4	1.008	4.032	0.90%
	Total	447.992	100.00%

Synonyms

Ferri-orangite (of Kalinin)
Ferrothorite (of Lacroix)

Literature, links & citation

Citations

1941Starik, I. E., Kravchenko, L. L. and Melikova, O. S. (1941), Doklady AN SSSR 32, N4, 254

Cite this entry

@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Ferrithorite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/ferrithorite-29959},
  note      = {Accessed 2026-05-11}
}