Difference between revisions of "Calcite"

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The most common crystalline form of [[calcium%20carbonate|calcium carbonate]]. Calcite is widely distributed throughout the world as [[chalk|chalk]], [[limestone|limestone]], and [[marble|marble]]. Major deposits were formed from ancient sea beds and hard water deposits (e.g., stalactites). Iceland is famous for producing large clear birefractive calcite crystals that are used in optical systems ([[Iceland%20spar|Iceland spar]]). In addition to clear colorless crystals, calcite may also appear white or pale shades of other colors depending on the crystal size and the presence of impurities. Marble is limestone that has been metamorphosed to form compact crystals of calcite. Calcite has been gathered or mined since Paleolithic times. In the form of chalk, calcite was powdered for use as a [[pigment]] and as an ingredient in the manufacture of [[steel]], [[cement]], and [[glass]]. Limestone and marble are used for sculpture and buildings.
 
The most common crystalline form of [[calcium%20carbonate|calcium carbonate]]. Calcite is widely distributed throughout the world as [[chalk|chalk]], [[limestone|limestone]], and [[marble|marble]]. Major deposits were formed from ancient sea beds and hard water deposits (e.g., stalactites). Iceland is famous for producing large clear birefractive calcite crystals that are used in optical systems ([[Iceland%20spar|Iceland spar]]). In addition to clear colorless crystals, calcite may also appear white or pale shades of other colors depending on the crystal size and the presence of impurities. Marble is limestone that has been metamorphosed to form compact crystals of calcite. Calcite has been gathered or mined since Paleolithic times. In the form of chalk, calcite was powdered for use as a [[pigment]] and as an ingredient in the manufacture of [[steel]], [[cement]], and [[glass]]. Limestone and marble are used for sculpture and buildings.
  
[[File:calcite.jpg|thumb|Calcite]]
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[[File:Calcite crystal pendants.jpg|thumb|Crystals pendant<br>MFA# 13.3516]]
  
 
== Synonyms and Related Terms ==
 
== Synonyms and Related Terms ==
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File:calcite.jpg|Calcite
 
File:Calcite C100x.jpg|Calcite
 
File:Calcite C100x.jpg|Calcite
 
File:mcalcite plmp.jpg|Plane polarized light micrograph of calcite
 
File:mcalcite plmp.jpg|Plane polarized light micrograph of calcite

Revision as of 07:53, 11 August 2020

Egyptian dish
MFA# 11.1157

Description

The most common crystalline form of Calcium carbonate. Calcite is widely distributed throughout the world as Chalk, Limestone, and Marble. Major deposits were formed from ancient sea beds and hard water deposits (e.g., stalactites). Iceland is famous for producing large clear birefractive calcite crystals that are used in optical systems (Iceland spar). In addition to clear colorless crystals, calcite may also appear white or pale shades of other colors depending on the crystal size and the presence of impurities. Marble is limestone that has been metamorphosed to form compact crystals of calcite. Calcite has been gathered or mined since Paleolithic times. In the form of chalk, calcite was powdered for use as a Pigment and as an ingredient in the manufacture of Steel, Cement, and Glass. Limestone and marble are used for sculpture and buildings.

Crystals pendant
MFA# 13.3516

Synonyms and Related Terms

calcium carbonate; marble; limestone; Iceland spar; dogtooth spar; dog-tooth spar; nailhead spar; satin spar; calcareous spar; calc spar; calcspar; calcite (It., Fr., Port.); Kalzit, Calcit (Deut.); calcita (Esp.); calciet (Ned.); calcium salt of carbonic acid; Pigment White 18; CI 7720

FTIR (MFA)

Calcite (Egyptian limestone).TIF

Raman (MFA)

Calcite marble, 50X, laser 532 nm copy.tif

XRD

CALCITE1.jpg


Risks

ThermoFisher SDS

Physical and Chemical Properties

Rhombohedral crystal system. Perfect cleavage in three directions. Fracture = conchoidal. High birefringence. Can doubly refract light. Aged surfaces of calcite may fluoresces purple or blue in ultraviolet light; freshly cleaved surfaces are white to yellow. Reacts with acids to evolve carbon dioxide. Luster = vitreous. Streak = white.

Composition CaCO3
CAS 471-34-1
Mohs Hardness 3.0
Density 2.71-2.72
Molecular Weight mol. wt. = 100.09
Refractive Index 1.486; 1.658; (1.566)

Comparisons

Properties of Common Abrasives

Additional Images

Sources Checked for Data in Record

  • R. Gettens, E. West Fitzhugh, R.Feller, "Calcium Carbonate Whites", Artists Pigments, Vol. 2., A. Roy ed. Oxford University Press, Oxford, 1993.
  • Thomas Gregory, The Condensed Chemical Dictionary, Reinhold Publishing, New York, 3rd ed., 1942 Comment: Mohs =2
  • Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976 Comment: Mohs=3
  • R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
  • G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 138, Mohs=3
  • C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979
  • Jack Odgen, Jewellery of the Ancient World, Rizzoli International Publications Inc., New York City, 1982
  • A.Lucas, J.R.Harris, Ancient Egyptian Materials and Industries, Edward Arnold Publishers Ltd., London, 4th edition, 1962

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