Background Information
Plaster of Paris comes from a rock called gypsum. Gypsum is made up of tiny crystals and ranges from yellowish-white to a bluish-white in colour. It is found mostly in Italy, Spain and Egypt, but is quite common in some parts of Britain. Gypsum is heated to between 300 and 400 degrees centigrade and then ground up to make plaster of Paris.
Plaster of Paris is a white powder that sets hard when mixed with water. As the plaster sets, it gives off quite a lot of heat. It is used to make a smooth surface on walls and ceilings and to hold broken bones together while they heal. Plaster is also very good for moulding and modelling.
Fossils are natural models made by different rocks and minerals, especially limestone. An animal dies and its body gradually rots away. Sometimes, the shape of the animal's body is left behind in mud, sand or wet clay. Over millions of years, particles of rock are dissolved by rainwater and carried into the shape. Sometimes, these rock particles are left behind and very gradually a fossil is formed. Find out more about fossils by following the links from this site.
