Thulite

{Ca2}{Al,Mn3+3}(Si2O7)(SiO4)O(OH)
Also known as
  • Manganoan Zoisite
  • Rosaline
  • Thulit
  • +1 more
Variety of
Zoisite
ZoisiteCa2Al3[Si2O7][SiO4]O(OH)

Where it forms, where it's found

Geological setting

Much of the so-called thulite from granite pegmatites, particularly in North Carolina, has proven to be clinothulite (Richard C. Erd, unpublished data, 1996).

Type locality
Øvstebø
  1. Kleppan
  2. Sauland
  3. Hjartdal
  4. Telemark
  5. Norway

59.6270°, 8.9406°

137recorded occurrences
Source · OpenStreetMap

Physical

Colour
pink

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
8OOxygenOxygen1315.999207.987
36.80%
25MnManganeseManganese354.938164.814
29.16%
14SiSiliconSilicon328.08584.255
14.91%
20CaCalciumCalcium240.07880.156
14.18%
13AlAluminiumAluminium126.98226.982
4.77%
1HHydrogenHydrogen11.0081.008
0.18%
Total565.202100.00%

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

From Mindat formula

Synonyms

  • Manganoan Zoisite
  • Rosaline
  • Thulit
  • Thulita

Literature, links & citation

Citations
  1. 1942Schaller, W. T., Glass, Jewell J. (1942) Occurrence of pink zoisite (thulite) in the United States. American Mineralogist, 27 (7) 519-524
  2. 1981Abrecht, J. (1981) Pink zoisite from the Aar Massif, Switzerland. Mineralogical Magazine, 44 (333) 45-49 doi:10.1180/minmag.1981.44.333.05 DOI: 10.1180/minmag.1981.44.333.05
  3. 1993Clark, A. M. (1993) Hey's Mineral Index - Mineral Species, Varieties and Synonyms (3rd ed.). Natural History Museum.
  4. 2002Langer, K., Tillmanns, E., Kersten, M., Almen, H., Arni, R. K. (2002) The crystal chemistry of Mn3+ in the clino- and orthozoisite structure types, Ca2M33+[OH|O|SiO4|Si2O7]: A structural and spectroscopic study of some natural piemontites and “thulites” and their synthetic equivalents. Zeitschrift für Kristallographie - Crystalline Materials, 217 (11). 563-580 doi:10.1524/zkri.217.11.563.20780DOI: 10.1524/zkri.217.11.563.20780
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Thulite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/thulite-3955},
  note      = {Accessed 2026-05-11}
}