Ichnusaite (pronounced iknusa-ait) is a very rarely found mineral. Ichnusaite is a natural compound of thorium and molybdenum with the formula Th(MoO<sub>4</sub>)<sub>2</sub>÷3H<sub>2</sub>O. It was discovered in Su Seinargiu, Sarroch, Cagliari, Sardegna, Italy in 2013. The name is from the old Greek name of Sardinia, ÃÂÃÂýÿÃÂ
ÃÂÃÂñ, Ichnusa.<br /> This locality is also a place of discovery of the second natural thorium molybdate - nuragheite.
Occurrence and association
Muscovite, nuragheite, and xenotime-(Y) are the associates of ichnusaite.
Notes on chemistry
Ichnusaite is chemically pure.
Crystal structure
The main features of the crystal structure of ichnusaite are:
- electroneutral Th(MoO<sub>4</sub>)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub> (100) sheets
- ThO<sub>7</sub>(H<sub>2</sub>O)<sub>2</sub> and MoO<sub>4</sub> polyhedra polymerize to give the above sheets
- sheets are stacked along [100] and held by hydrogen bonds
Bibliography
- Orlandi, P., Biagioni, C., Bindi, L. und Nestola, F. (2013) Ichnusaite, IMA 2013- 087. CNMNC Newsletter No. 18, December 2013, page 3255; Mineralogical Magazine, 77, 3249-325
- http://rruff.geo.arizona.edu/AMS/result.php?mineral=Ichnusaite
- https://web.archive.org/web/20160521090233/http://ammin.geoscienceworld.org/content/99/10/2089
- https://arpi.unipi.it/handle/11568/638691#.Vr93OUKuAt4
- http://www.degruyter.com/dg/viewarticle/j$002fammin.2014.99.issue-10$002fam-2014-4844$002fam-2014-4844.xml
- https://www.bbc.com/news/science-environment-35569659
References