Plaster of Paris consisting of a fine white powder which hardens when moistened and allowed to dry. Plaster of Paris is also known as Gypsum Plaster (CaSO4.1/2 H2O) OR (2CaSO4.H2O). Its chemical name is ‘Calcium sulphate hemihydrates’. It is a white powdery hydrated calcium sulphate.

1. Plaster of Paris

2. What is Plaster of Paris?
 Plaster of Paris consisting of a fine white
powder which hardens when moistened
and allowed to dry. Plaster of Paris is also
known as Gypsum Plaster (CaSO4.1/2
H2O) OR (2CaSO4.H2O). Its chemical
name is ‘Calcium sulphate hemihydrates’.
It is a white powdery hydrated calcium
sulphate.

3. What is the use of Plaster of Paris?
 The uses of plaster of Paris are as follows:
 It is used in medicine to make plaster casts to immobilize broken
bones while they heal, though some orthopaedic casts are made
of fibreglass or thermoplastics.
 It is commonly used to precast and hold parts of ornamental
plaster work placed on ceilings and cornices.
 It is used for making toys, blackboard chalk, cheap ornaments,
cosmetics, decorative materials and casts for statues.
 It is also used for beautification of ceilings of buildings and
houses.
 It is also used for the setting of fractured bones in the right
position.
 It is used by dentists for making casts of demure.
 It is used in chemistry laboratories for sealing air-gaps in
apparatus where air tight arrangement is required.
 It is used for making walls of homes smooth before painting them
and for making beautiful designs on the ceilings of houses and
other buildings.
 It is also used as a fire proofing material.

4. How plaster of Paris is made?
 Plaster of Paris is made by heating the mineral
gypsum. Large deposits were originally found
outside of Paris in France, that why it is known as
plaster of Paris.
 When gypsum is heated to about 150 degree
Celsius, it loses water and produces the powder
which is known as plaster of Paris.
 The chemical formula for plaster of Paris is
CaSO4.1/2H2O.
 When water is added to the plaster of Paris
powder it rehydrates (absorbs water) and quickly
hardens. With an additive to retard the set, it is
called wall, or hard wall, plaster, which can
provide passive fire protection for interior
surfaces.

5. Use of Plaster of Paris in history
 Plaster of Paris does not generally shrink or crack
when dry, making it an excellent medium for casting
moulds. It is commonly used to precast and hold
parts of ornamental plasterwork placed on ceilings
and cornices. It is also used in medicine to make
plaster casts to immobilize broken bones while they
heal, though many modern orthopaedic casts are
made of fibreglass or thermoplastics. Some sculptors
work directly in plaster of Paris, as the speed at which
the plaster sets gives the work a sense of immediacy
and enables the sculptor to achieve the original idea
quickly. In medieval and Renaissance
times, gesso (usually made of plaster of Paris mixed
with glue) was applied to wood panels, plaster, stone,
or canvas to provide the ground for tempera and oil
painting.

6. Plaster of Paris manufacturers in
Rajasthan
 There are many Plaster of Paris
manufacturers in Rajasthan. You can
contact them and enquire them about
what you need.