#carnalite

KCl.MgCl2.6H2O

Mohr's salt

FeSO4.(NH4)2SO4.6H2O

Potash alum

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.