Starkeyite

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Starkeyite[1][2]
Mineralogical name Starkeyite, Leonhardtite
Chemical name Magnesiumsulfate Tetrahydrate
Trivial name
Chemical formula MgSO4•4H2O
Other forms Kieserite (MgSO4•H2O)
Sanderite (MgSO4•2H2O)
Pentahydrite (MgSO4•5H2O)
Hexahydrite (MgSO4•6H2O)
Epsomite (MgSO4•7H2O)
Meridianiite (MgSO4•11H2O)
Magnesium 12-Hydrate
Crystal system monoclinic
Crystal structure
Deliquescence humidity 20°C
Solubility (g/l) at 20°C
Density (g/cm³) 2.01 g/cm3
Molar volume 95.87 cm3/mol
Molar weight 192.43 g/mol
Transparency translucent to opaque
Cleavage
Crystal habit
Twinning
Phase transition
Chemical behavior
Comments unstable in air
Crystal Optics
Refractive Indices nx = 1.49
ny = 1.491
nz = 1.497
Birefringence Δ = 0.007
Optical Orientation positive
Pleochroism
Dispersion 22°
Used Literature
[Lide:1995]Title: CRC Handbook of Chemistry and Physics
Author: Lide D.R.
Link to Google Scholar
[Robson:1927]Title: The System MgSO4-H2O from 68 to 240°
Author: Robson H.L.
Link to Google Scholar



Weblinks

Literature

[Lide:1995]Lide D.R. (eds.) Lide D.R. (1995): CRC Handbook of Chemistry and Physics, CRC PressLink to Google Scholar
[Robson:1927]Robson H.L. (1927): The System MgSO4-H2O from 68 to 240°. J. Amer. Chem. Soc., 49 (11), 2772-2783Link to Google Scholar