5 things you didn’t know about…polyhalite
1. Polyhalite is an evaporite mineral, a hydrated sulfate of potassium, calcium and magnesium – K2Ca2Mg(SO4)4.
2. Its name derives from the Greek words meaning ‘many salts’, reflecting its composition.
3. It makes up 7% of the rock in the salt deposits at Stassfurt, Germany.
4. Polyhalite was formed during the evaporation of prehistoric seas in the Permian period.
5. Polysulphate comes from the polyhalite layer of rock, more than 1,200 metres below the North Sea off the North Yorkshire coast, UK. It was deposited 260 million years ago, 150–170m below the potash seam at Boulby Mine.
To find out more about the polyhalite deposit in the UK, read our Q&A with the CEO of Sirius Minerals in our September issue.
