Wyomingite Explained

Wyomingite is a type of volcanic rock. Specifically, it is a diopside-leucite phlogopite lamproite.^[1] It is a potassium enriched, alkaline, basic, phonolite first found in the Leucite Hills of Sweetwater County, Wyoming.^[2] Wyomingites are between foidite and tephri-phonolite in composition (in the QAPF classification) and contain leucite (20-25%), augite, phlogopite, apatite, calcite, magnetite and small amounts of olivine (but the latter may be absent).^[3] Silica (SiO₂) content is between 48.9% and 51.7%. Common groundmass includes potassium-richterite. Wyomingite has also been found at two locations in Australia: West Kimberley,^[4] and near Ballina, New South Wales.^[5]

See also

• – the state gemstone of Wyoming

Notes and References

1. M. P. Orlova (1991) CLASSIFICATION AND NOMENCLATURE OFROCKS OF THE LAMPROITE SERIES, International Geology Review, 33:3, 263-268, https://doi.org/10.1080/00206819109465691 pp. 265
2. Sobolev . V. S. . Bazarova . T. Ju. . Yagi . Kenzo . 1975-12-01 . Crystallization temperature of wyomingite from Leucite Hills . Contributions to Mineralogy and Petrology . en . 49 . 4 . 301–308 . 10.1007/BF00376182 . 1975CoMP...49..301S . 129836750 . 1432-0967.
3. Gupta, A.K. (2015) Experimental Studies on K-Rich Rocks. In Origin of Potassium-rich Silica-deficient Igneous Rocks. Springer India. https://doi.org/10.1007/978-81-322-2083-1_13 pages 80 and 82
4. Web site: Oscar Plug, Ellendale, Derby-West Kimberley Shire, Western Australia, Australia .
5. Web site: Phlogopite lamproite .