Magadiite is a hydrous sodium silicate mineral (NaSi7O13(OH)3·4(H2O)) which precipitates from alkali brines as an evaporite phase. It forms as soft (Mohs hardness of 2) white powdery monoclinic crystal masses.[1][2] The mineral is unstable and decomposes during diagenesis leaving a distintive variety of chert (Magadi-type chert).[3]
The mineral was first described by Hans P. Eugster in 1967 for an occurrence in Lake Magadi, Olduvai Gorge, Kenya.[2][3] It is also reported from alkalic intrusive syenites as in Mont Saint-Hilaire, Canada.[1]
References[]
- ↑ 1,0 1,1 http://www.handbookofmineralogy.org/pdfs/Magadiite.PDF Mineral Handbook
- ↑ 2,0 2,1 http://www.webmineral.com/data/Magadiite.shtml Webmineral
- ↑ 3,0 3,1 Encyclopedia of Sediments & Sedimentary Rocks, Springer, 2003, p. 417, ISBN 1402008724