Opal-A

Variety of
Opal
OpalSiO2 · nH2O

Where it forms, where it's found

14recorded occurrences
Source · OpenStreetMap

Varieties

Literature, links & citation

Citations
  1. 1971Jones, J. B., Segnit, E. R. (1971) The nature of opal I. nomenclature and constituent phases. Journal of the Geological Society of Australia, 18 (1) 57-68 doi:10.1080/00167617108728743DOI: 10.1080/00167617108728743
  2. 2008Day, R., Jones, B. (2008) Variations in Water Content in Opal-A and Opal-CT from Geyser Discharge Aprons. Journal of Sedimentary Research, 78 (4) 301-315 doi:10.2110/jsr.2008.030DOI: 10.2110/jsr.2008.030
  3. 2022Lee, Seungyeol, Xu, Huifang, Xu, Hongwu (2022) Reexamination of the structure of opal-A: A combined study of synchrotron X-ray diffraction and pair distribution function analysis. American Mineralogist, 107 (7) 1353-1360 doi:10.2138/am-2022-8017DOI: 10.2138/am-2022-8017
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Opal-A — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/opal-a-47868},
  note      = {Accessed 2026-05-11}
}