Gypsum is a naturally occurring mineral, calcium sulphate dihydrate, [CaSO₄.2H₂O], and is found in many different structures and colours.

This sedimentary rock was formed over many millions of years by the evaporation of seawater. The evaporation phase, which lasted thousands of years, led to the formation of gypsum deposits, in thick layers.

Gypsum seams were subsequently buried over a period of time through natural subsidence, and lay preserved deep in the earth for millions of years.

Gypsum deposits were brought nearer to the earth’s surface during the last Ice Age by the erosive effect of glaciers and the deep incision of river valleys by the glacial melt water.