Uranothorite

Where it forms, where it's found

163recorded occurrences

Source · OpenStreetMap

Radioactivity

Chemical composition

Constituent elements: Mass composition breakdown
Element Atoms At. mass g/mol Mass g/mol Mass share
92UUranium Uranium 1 238.029 238.029
42.34%
90ThThorium Thorium 1 232.038 232.038
41.28%
8OOxygen Oxygen 4 15.999 63.996
11.38%
14SiSilicon Silicon 1 28.085 28.085
5.00%
Total 562.148 100.00%
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
92UUranium	Uranium	1	238.029	238.029	42.34%
90ThThorium	Thorium	1	232.038	232.038	41.28%
8OOxygen	Oxygen	4	15.999	63.996	11.38%
14SiSilicon	Silicon	1	28.085	28.085	5.00%
	Total	562.148	100.00%

Synonyms

U-thorite
Uranoan thorite
Uranothorit
Uranotorita
Wisaksonite

Literature, links & citation

Citations

1927Ellsworth, H. V. (1927) I. Uranothorite from the MacDonald Mine, Hybla, Ontario. American Mineralogist, 12 (10) 368-372
1932KIMURA, Kenjiro, MIYAKE, Yasuo (1932) On Enalite, a New Variety of Uranothorite, Found in Naegi, Gifu Prefecture. NIPPON KAGAKU KAISHI, 53. 93-100 doi:10.1246/nikkashi1921.53.93DOI: 10.1246/nikkashi1921.53.93
1951Pabst, A. (1951) X-ray examination of uranothorite. American Mineralogist, 36 (7-8) 557-562
1952Phair, George, Shimamoto, Kiyoko Onoda (1952) Hydrothermal uranothorite in fluorite breccias from the Blue Jay mine, Jamestown, Boulder County, Colorado. American Mineralogist, 37 (7-8) 659-666
1955Nagashima, Otokichi, Sakurai, Kin-ich (1955) Uranothorite from Kamiotomo, Iwate Prefecture. Journal of the Mineralogical Society of Japan, 2 (3) 210-211 doi:10.2465/gkk1952.2.210 DOI: 10.2465/gkk1952.2.210

Cite this entry

@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Uranothorite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/uranothorite-8611},
  note      = {Accessed 2026-05-11}
}