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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. |
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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. |
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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. |
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Plaster of Paris was given its name because it was first
found in French quarries. |
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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.
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| Specific gravity |
2.3 |
It is a
very light stone. |
| Crystal Shape |
Monoclinic |
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Alabaster is a kind of gypsum that is used for carvings. |
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Links:
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Printer
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Citations:
Fuller, Sue. Rocks
& Minerals. London: Dorling Kindersley, 1995.
“Gypsum.”
12 Dec. 2005.
<http://www.sdnhm.org/fieldguide/minerals/gypsum.html>.
“Gypsum.”
24 Oct. 2005.
<http://www.minerals-n-more.com/Gypsum_Info.html>.
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