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First you need to recognize that "plaster" is not a singularly defined material; it is a family of quite different materials that harden by different mechanisms. The three most common plasters are (1) Plaster of Paris, (2) Lime Plaster, and (3) Cement Plaster.
(1) Plaster of Paris is CaSO4.H2O, a partially-dehydrated form of Gypsum, which is a hydrated Calcium Sulfate crystal CaSO4.2H2O. When Plaster of Paris is mixed with water, it re-hydrates and turns back into Gypsum, which then hardens into a material similar to mortar or concrete but considerably softer. Water is the material that makes Plaster of Paris harden.
(2) Limestone When exposed to atmosphere the Calcium hydroxide turns back to limestone, causing the plaster to set.
(3) Cement Plaster is a mixture of Portland Cement powder, sand or other filler, water, and either Plaster of Paris or Lime Plaster. Due to the great variety of minerals that makeup Portland Cement and Cement Plaster, the hardening is a complex process that cannot be ascribed to the action of any one of the ingredients.
What else can I help you with?
What minerals is used to make drywall plaster and chalk?
Gypsum is the mineral used to make drywall plaster and chalk. It is a soft sulfate mineral with a variety of uses in construction and manufacturing due to its ability to harden when mixed with water.
What rock or mineral makes dry wall?
It's made from gypsum plaster, so mixing water with calcium sulphate hemihydrate then heating it to produce plaster and using the plaster to produce the drywall.
Is Plaster of Paris a mineral?
yes. Plaster of Paris is a powdered rock made from the mineral gypsum.
What mineral is used in making plaster?
Gypsum is the mineral used in making plaster. When gypsum is heated and mixed with water, it forms a paste that hardens to create plaster.
What is plaster boards made from?
It is a mixture of gypsum, a naturally occurring mineral, and water.
What mineral is used in plaster of Paris and dry wall?
It's calcium sulphate dihydrate, or 'Gypsum'.
Which substance readily harden when mixed with water is lime or silica or plaster of Paris or granite?
Plaster of Paris readily hardens when mixed with water.
How does plaster of Paris kill rats?
Plaster of Paris sets when it comes into contact with water. If a rat eats it, and drinks water it will activate and harden in the rats stomach.
What mineral is used to make plaster?
biotite mica is used to make plaster and other construction materials
What happens when plaster of Paris is exposed to air?
When plaster of Paris is exposed to air, it undergoes hydration, which means it reacts with water vapor in the air to form a solid material. This process causes the plaster to harden and set into a rigid structure.
What happens of you put plaster on a water balloon?
If plaster is put on a water balloon, the plaster will absorb the water content from the balloon, causing it to harden. This can result in the balloon deflating as its water content is absorbed by the plaster, leaving behind a hardened plaster shell in the shape of the balloon.
Does plaster of Paris go bad over time?
Yes, plaster of Paris can go bad over time if it is exposed to moisture or if it is stored improperly. Moisture can cause the plaster to harden and become unusable. It is important to store plaster of Paris in a dry and airtight container to prevent it from going bad.
