Gypsum: Difference atween revisions

Gypsum
	Fibrous gypsum selenite shawin its translucent property.
General
Category	Sulfate meenerals
Formula; (repeatin unit)	CaSO4·2H2O
Strunz clessification	07.CD.40
Creestal seestem	Monoclinic 2/m – Prismatic
Space group	Monoclinic 2/m
Unit cell	a = 5.679(5) Å, b = 15.202(14) Å, c = 6.522(6) Å; β = 118.43°; Z=4
Identification
Colour	Colourless tae white; mey be yellae, tan, blue, pink, broun, reiddish brown or gray due tae impurities
Creestal habit	Massive, flat. Elangatit an generally prismatic crystals
Twinnin	Very common on {110}
Cleavage	Perfect on {010}, distinct on {100}
Fractur	Conchoidal on {100}, splintery parallel tae [001]
Tenacity	Flexible, inelastic.
Mohs scale haurdness	1.5–2 (definin meeneral for 2)
Skinkle	Vitreous tae silky, pearly, or waxy
Streak	White
Diaphaneity	Transparent tae translucent
Speceefic gravity	2.31–2.33
Optical properties	Biaxial (+)
Refractive index	nα = 1.519–1.521; nβ = 1.522–1.523; nγ = 1.529–1.530
Birefringence	δ = 0.010
Pleochroism	None
2V angle	58°
Fusibility	5
Solubility	Het, dilute HCl
References
Major varieties
Satin spar	Pearly, fibrous masses
Selenite	Transparent and bladed crystals
Alabast	Fine-grained, slightly colored

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Inline

Reveision as o 16:13, 2 Mairch 2018

Gypsum is a very soft sulphate mineral composed o calcium sulphate dihydrate, withchemical formula CaSO₄·2H₂O.^[3] It can be uised as a fertilizer, is the main constituent in mony furms o plaister an is widely mined. A very fine-grained white or lichtly tinted variety o gypsum, cried alabast, haes been uised for sculpture bi mony culturs includin Auncient Egyp, Mesopotamie an the Nottingham alabasts o medieval Ingland. It is the definition o a hairdness o 2 on the Mohs scale o meeneral hardness. It furms as an evaporite meeneral an as a hydration product o anhydrite.

↑ Gypsum in Handbook of Mineralogy
↑ Gypsum at Mindat
↑ ^a ^b Cornelis Klein and Cornelius S. Hurlbut, Jr., 1985, Manual of Mineralogy, John Wiley, 20th ed., pp. 352–353, ISBN 0-471-80580-7

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 | var3 = [[Alabast]]|var3text = Fine-grained, slightly colored
 }}
-'''Gypsum''' is a very saft [[sulfate meeneral]] componed o [[calcium sulfate]] [[dihydrate]], wi the [[chemical formula]] CaSO<sub>4</sub>·2H<sub>2</sub>O.<ref name=Cornelis/> It can be uised as a [[fertilizer]], is the main constituent in mony furms o [[plaister]] an is widely mined.  A very fine-grained white or lichtly tinted variety o gypsum, cried [[alabast]], haes been uised for [[sculpture]] bi mony culturs includin [[Auncient Egyp]], [[Mesopotamie]] an the [[Nottingham alabast]]s o medieval Ingland.  It is the definition o a hairdness o 2 on the [[Mohs scale o meeneral hardness]]. It furms as an [[evaporite]] meeneral an as a hydration product o [[anhydrite]].
+'''Gypsum''' is a very soft [[sulphate mineral ]] composed o [[calcium sulphate]] [[dihydrate]], with[[chemical formula]] CaSO<sub>4</sub>·2H<sub>2</sub>O.<ref name=Cornelis/> It can be uised as a [[fertilizer]], is the main constituent in mony furms o [[plaister]] an is widely mined.  A very fine-grained white or lichtly tinted variety o gypsum, cried [[alabast]], haes been uised for [[sculpture]] bi mony culturs includin [[Auncient Egyp]], [[Mesopotamie]] an the [[Nottingham alabast]]s o medieval Ingland.  It is the definition o a hairdness o 2 on the [[Mohs scale o meeneral hardness]]. It furms as an [[evaporite]] meeneral an as a hydration product o [[anhydrite]].
 ==References==