Gypsum

  • What is it and where is it formed?  Gypsum is a sedimentary mineral.  It is found in layers that were formed under salt water millions of years ago.  The water evaporated and left the minerals.

  • How and where is it mined?  Gypsum is mined in quarries or underground mines.  It is mined in France, Mexico, Sicily, Utah, Colorado, Nevada, Texas, and California.

  • What is it used for?  Gypsum is used in wallboard, big sheets of a plaster-like substance covered with paper.  Wallboard is used to make new walls in buildings.  It is also used in Plaster of Paris, cement, fertilizer, and ornamental stone.  It is also used in cement to keep it from hardening too fast. When water is added to gypsum powder, it becomes hard as rock.  This is what is used to make plaster casts for broken arms and legs.

  • Interesting Information:

    • Alabaster is a kind of gypsum that is used for carvings.

    • Plaster of Paris was given its name because it was first found in French quarries.

Gypsum

Gypsum
Mineral Characteristic What the
mineralogists say		 Kid's Guide:  What it REALLY means!
Chemical Symbol CaSO42H2O It has oxygen, calcium, sulfur, and hydrogen in it.
Color

White, colorless, or gray

 It is mostly found in white, gray or it has no color.
Streak

White

 When the stone is rubbed on a white plate, it leaves a white powder.  If the stone was crushed, this is what color the powder would be.
Transparency

Transparent to opaque

 Gypsum might be clear enough to see through, a little blurry, or so cloudy that you can’t see through it at all.
Luster

Vitreous to pearly

 When light shines on it, it looks glassy or pearly.
Cleavage

Good in one direction

 If you hit it with a hammer, it would break into layers going in one direction.
Fracture

Conchoidal and splintery

 This mineral doesn’t break into pieces often but when it does, it doesn’t do it evenly.  The splinters would be smooth.
Magnetism

None.

 It will not attract, or be attracted to, a magnet.
Hardness

2

It is so soft that it can be scratched by a fingernail.
Specific gravity

2.3

 It is a very light stone.
Crystal Shape

Monoclinic

Monoclinic