G for gypsum

Gypsum is a common mineral. It is quite soft and is usually white or grey in colour.

Fact:

Gypsum has many uses in industry, and if you've ever broken your arm or leg you should be grateful for gypsum too.

Do you know why?

Gypsum is used to make plaster casts.
When gypsum is ground to a powder and mixed with water it forms wet plaster. If you soak bandages in this mixture they will set very hard, holding bones in place so that they can heal.