McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams

Home » Minerals » Gypsum

Gypsum


An important construction material that has been used for thousands of years



What is Gypsum?



Gypsum is an evaporite mineral most commonly found in layered sedimentary deposits in association with halite, anhydrite, sulfur, calcite and dolomite. Gypsum (CaSO4.2H2O) is very similar to Anhydrite (CaSO4). The chemical difference is that gypsum contains two waters and anhydrite is without water. Gypsum is the most common sulfate mineral.


Physical Properties of Gypsum

Chemical Classification sulfate
Color clear, colorless, white, gray, yellow, red, brown
Streak white
Luster vitreous, silky, sugary
Diaphaneity transparent to translucent
Cleavage perfect
Mohs Hardness 2
Specific Gravity 2.3
Diagnostic Properties cleavage, specific gravity, low hardness
Chemical Composition hydrous calcium sulfate, CaSO4.2H2O
Crystal System monoclinic
Uses


Uses of Gypsum?



Gypsum uses include: manufacture of wallboard, cement, plaster of Paris, soil conditioning, a hardening retarder in Portland cement. Varieties of gypsum known as "satin spar" and "alabaster" are used for a variety of ornamental purposes, however their low hardness limits their durability.


Gypsum from Michigan
Gypsum from Grand Rapids, Michigan. Specimen is approximately 4 inches (10 centimeters) across.


Gypsum from virginia
Gypsum from North Holston, Virginia. Specimen is approximately 1-1/2 inches (3.8 centimeters) across.


Satin spar Gypsum
Satin spar, a fibrous variety of gypsum from Derbyshire, England. Specimen is approximately 3 inches (7.6 centimeters) across.


Alabaster Gypsum
Alabaster, a variety of gypsum, from Pomaia, Italy. Specimen is approximately 3 inches (7.6 centimeters) across.


Gypsum translucency
The translucent characteristic of alabaster, a variety of gypsum, from Pomaia, Italy. Specimen is approximately 3 inches (7.6 centimeters) across.



Find it on Geology.com




More from Geology.com


Organic Gems
Organic Gems are gems formed from or by plants or animals. They might also be fossils.
Plate Tectonics
Plate Tectonics: Articles and maps about plate tectonics and the interior of Earth.
Fossils
Fossils: Learn about fossils and fossil discoveries around the world.
largest volcano
The Largest Volcanoes on Earth might not be the ones that you are thinking about.
US Gemstones
United States Gemstones: A diversity of gemstones are produced in the United States.
US Diamond Mines
US Diamond Mines: Did you know that diamonds can be found in the United States?
shale gas
Shale Gas is natural gas trapped within shale. It is a growing source of US supply.
Plate Tectoncs
Zoom in on Plate Boundaries: See the details of plate tectonics in satellite view.


 Gypsum
Satin spar, a fibrous variety of gypsum from Derbyshire, England. Specimen is approximately 4 inches (10 centimeters) across.




gypsum wallboard and plaster
Wallboard and construction plaster are the primary industrial uses of gypsum in the United States.Photo © George Peters and iStockphoto.


Alabaster gypsum jar
Jar made of beautiful translucent alabaster gypsum by David MacFarlane, photo © David MacFarlane and iStockphoto.


Selenite Gypsum
Selenite, a variety of gypsum from Penfield, New York. Specimen is approximately 2-1/2 inches (6.4 centimeters) across.


Gypsum from New York
Selenite, a variety of gypsum from Penfield, New York. Specimen is approximately 2-1/2 inches (6.4 centimeters) across.


Mineral Information
 Andalusite
 Anhydrite
 Apatite
 Arsenopyrite
 Augite
 Azurite

 Barite
 Bauxite
 Beryl
 Biotite
 Bornite

 Calcite
 Cassiterite
 Chalcocite
 Chalcopyrite
 Chlorite
 Chromite
 Chrysoberyl
 Cinnabar
 Clinozoisite
 Copper
 Cordierite
 Corundum
 Cuprite
 Diamond
 Diopside
 Dolomite

 Enstatite
 Epidote

 Fluorite

 Galena
 Garnet
 Glauconite
 Gold
 Graphite
 Gypsum

 Halite
 Hematite
 Hornblende

 Ilmenite

 Jadeite

 Kyanite
 Limonite

 Magnesite
 Magnetite
 Malachite
 Marcasite
 Molybdenite
 Monazite
 Muscovite

 Nepheline
 Nephrite

 Olivine
 Orthoclase

 Plagioclase
 Prehnite
 Pyrite
 Pyrophyllite
 Pyrrhotite

 Quartz

 Rhodochrosite
 Rhodonite
 Rutile
 Scapolite
 Serpentine
 Siderite
 Sillimanite
 Silver
 Sodalite
 Sphalerite
 Spinel
 Spodumene
 Staurolite
 Sulfur
 Sylvite

 Talc
 Titanite
 Topaz
 Tourmaline
 Turquoise

 Uraninite

 Witherite
 Wollastonite

 Zircon
 Zoisite


San Andreas Fault
Types of Volcanic Eruptions
Volcanoes!
Rare Earth Elements
Who Owns The Arctic?
The Only Diamond Mine in the USA
Mineral Rights
What is a Debris Flow?




© 2005-2014 Geology.com. All Rights Reserved.
Images, code and content of this website are property of Geology.com. Use without permission is prohibited. Pages on this site are protected by Copyscape.