Gypsum

The word gypsum is derived from the Greek word gypsos, which means chalk or plaster.

Gypsum has five basic forms:

  • alabaster
  • gypsite or gypsum earth
  • rock gypsum
  • satin spar
  • selenite
For simplicity we'll just discuss ‘rock gypsum’ here.

Gypsum for construction

Although gypsum is mainly used in the manufacture of building products such as plaster, plasterboard and cement, you will also find it lots of other products around the house.

Gypsum in the home

Composed of hydrated calcium sulphate,  gypsum is used as an ingredient in canned vegetables, flour (white bread), ice cream and blue cheese. In beer brewing, gypsum can be used to 'harden' the water and in wine-making to improve clarity i.e. reduce cloudiness.

Fluoride is not the only mineral to be found in toothpaste, gypsum is also used to clean your teeth as a mild abrasive.

Gypsum is also used elsewhere in the bathroom as a colour additive for tablets (pharmaceuticals) and cosmetics. And should you have an accident and break a bone, you will find your limbs wrapped in a gauze bandage which has been dipped in 'plaster-of-Paris', which is most likely to have been made from gypsum.

The uses of gypsum do go on and on so we’ve included a few more in the pictures in the galleries below.

What does it look like?

Gypsum sample

Anhydrite is the ‘anhydrous’  form calcium sulphate,  which gets its name from the Greek  for ‘without water’.


In your shopping basket

Gypsum is used in pharmaceuticals, canned vegetables, beer brewing, baking, cheeses and preserves.

Industrial uses or around the home

Gypsum is used as a fertiliser, as animal bedding, in paper manufacture, pottery and ceramic products.

Key facts

Colour

Pure gypsum is white or 'colourless'. Impurities may give colour to local deposits.

Rock or mineral?

Gypsum, or hydrated calcium sulphate, is a mineral; its chemical formula is CaSO4.2H2O. Gypsum is a mineral that forms when sulphate- and calcium-rich salt water evaporates.

Hard or soft?

Gypsum is fairly soft and can easily be scratched with your fingernail.

Where is it mined?

Although gypsum is still mined in the East Midlands, the UK imports most of its gypsum from south-east Spain and Germany.

Can we recycle it?

Plasterboard and decorative plaster mouldings can be recycled, much like waste paper is recycled, into new plasterboard.

It is essential to our lives?

Gypsum is used extensively in construction, food and drink products and medical applications. However, we could seek alternatives to some of its uses. For example, in some countries they tend to use ceramic tiles as a wall covering.

Fun fact

Gypsum may be present on Mars. NASA Scientists observing the Gale Crater on Mars suspect the sediment mound at its centre contains gypsum, which may be the product of an ancient lake when Mars was a much warmer, wetter place.

Need more detail?

Download our gypsum factsheet