Solid phase
Official name
Magnesium(II) sulfate monohydrate
Secondary names
Magnesium sulphate monohydrate
CAS number
14168-73-1
Family
ionic solid
Class
normal salt
Compound type
sulfate
Comments
Magnesium sulfate monohydrate occurs as a mineral: Kieserite
Formula
Mg2+SO24H2O
Chemical formula
MgSO4•H2O
Elemental formula
(Mg2+) S O3 (O-)2 H2
Isotope mixture type
terrestrial abundance
6.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
Mg2+ Magnesium(II) cation element 1 0.3333333333333333 1 constituent cation main
(SO4)2 Sulfate anion chemical function 1 0.3333333333333333 1 anionic radical main
H2O Water molecule 1 0.3333333333333333 1 hydration main
Chemical functions
  Function Number
(SO4)2 1
ROH 2
Chemical bonds
  Bond Number
Mg2+O 2
OH 2
OH 2
4
Class
normal salts (07)
Type
hydrated simple normal salts (07.04)
Equivalent mineral
Kieserite
Phase type
crystalline
Crystal system
monoclinic
Crystal class
prismatic
Crystal class symbol
2/m (C2h)
Crystal spacegroup
C2/c
Molar mass
138.38 g/mol
Density
2.445 g/cm^3
State NTP
solid
Phase transitions
Phase transition type Other phases Temperature - Pressure
solid decomposition MgSO_4 200°C (473 K)
solid-solid MgSO4.6H2O below 68°C (341 K)
solid-solid MgSO4.6H2O above 42% RH
Refringence type
biaxial
Refringence sign
positive
Birefringence
0.064
Refraction index n_{\alpha}
1.520
Refraction index n_{\beta}
1.533
Refraction index n_{\gamma}
1.584
Dispersion V
relatively strong
Pure color
colorless
Color
colorless
Diaphaneity
transparent to translucent
Luster
vitreous