Magadiite

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. ^ a b http://www.handbookofmineralogy.org/pdfs/Magadiite.PDF Mineral Handbook
2. ^ a b http://www.webmineral.com/data/Magadiite.shtml Webmineral
3. ^ a b Encyclopedia of Sediments & Sedimentary Rocks, Springer, 2003, p. 417, ISBN 1402008724


List of minerals