Polyhalite explained

Polyhalite is a naturally occurring mineral fertilizer containing potassium, magnesium and calcium.

2 mins

It is mined in its natural state: there are no additional processes involved in its production, making it a sustainable fertilizer, with a low environmental footprint which has been registered for use in organic production.

A polyhalite crystal


Polyhalite has the following minimum contents:

  • Potassium 14% K2O from potassium sulfate.
  • Magnesium 6% MgO from magnesium sulfate.
  • Calcium 17% CaO from calcium sulfate


The mineral polyhalite was formed more than 200 million years ago, and can be found over 1,200 meters below the Earth’s surface, in the bedrock under the North Sea along England’s north-eastern coast. This natural fertilizer is produced exclusively by the Boulby mine in North Yorkshire, England. The Boulby mine is the first and only Polyhalite mine, making ICL the sole producer in the world.

The Boulby Mine plant in North Yorkshire, England