#zechstein

[icepickaxe]

Zechstein potash deposits in Werratal by Kali und Salz GmbH © K+S AG

[earthstory]

Salt mine of many hues When sea evaporate, often time and again as climate oscillates, very thick zones of salt can result, such as the Permian era (roughly 300-250 million years ago) Zechstein that underlies much of Europe. Near the type locality for the era near around the Russian city of Perm is an abandoned salt mine, where the evaporating waters were rich in potassium as well as sodium, and a mixture of evaporite minerals were deposited. These have created amazing swirls and psychedelic patterns om the tunnels, made of mixed halite (rock salt) and the potassium magnesium chloride mineral carnallite.

Named after a Prussian mining engineer, it only forms where the sea water has been hyper concentrated in a partly cut off basin in a hot climate to promote intense evaporation. It remains an important source of potash for use in fertilisers, since most potassium minerals such as feldspar have it firmly bound into a silicate structure. Colours range from transparent to yellow and red. Loz Image credit: Caters News Agency http://dailym.ai/1c6Dk4P http://www.mindat.org/min-906.html http://www.galleries.com/Carnallite

[earthstory]

Table salt The white or grey stuff you add to your food is a purified form of the mineral halite, produced by evaporating sea water or mined from the remnants of evaporated seas such as the Permian Zechstein that lies under the surface rocks of much of Europe. Sometimes though a lovely gemmy piece worthy of a mineral collection turns up, such as this bright blue crystal from the Intrepid potash mine in New Mexico. the specimen measures 8x4x2cm. Loz Image credit: Joe Budd/Rob Lavinsky/iRocks.com