Mineral phase
IMA name
Hydrohalite
CAS number
23724-87-0
Type
Class
non-silicate mineral
Compound type
halide
Chemical composition
Formula
$NaCl \bullet 2(H_2O)$
Chemical formula
NaCl•2(H2O)
Elemental formula
(Na+) (Cl-) H4 O2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Na^+$ Sodium cation element 1 constituent cation main
$Cl^-$ Chloride anion element 1 constituent anion main
$H_2O$ Water molecule 2 hydration main
Chemical functions
  Function Number
$R-OH$ 2
Chemical bonds
  Bond Number
$Na^+ \cdot Cl^-$ 6
$-O \dots H-$ 4
$-O-H$ 2
Oxides
Formula $Na_{2}O$ $H_{2}O$ $Cl$
Mass fraction (%) 32.8 38.14 37.53
Oxides comments
-8.47 % -O=Cl2

Strunz

Class
halides (03)
Division
simple halides, with H2O (03.B)
Family
M:X = 1:1 and 2:3 (03.BA)
Code
03.BA.05

Dana

Major class
halides (IV)
Class
anhydrous and hydrated halides (09)
Type
where AX (09.01)
Group
-Hydrohalite- group (09.01.02)
Code
09.01.02.01
Phase type
crystalline
Crystal system
monoclinic
Crystal class
prismatic
Crystal class symbol
2/m (C2h)
Crystal spacegroup
P2(1)/c
Molar mass
94.473 $g/mol$
Density
1.605 - 1.63 $g/cm^3$
State NTP
solid
Phase transitions
Phase transition type Other phases Temperature - Pressure
solid-liquid liquid H2O -0.1°C (273.05 K)
Refringence type
biaxial
Refringence sign
unknown
Birefringence
0
Refraction index $n_{\alpha}$
unknown
Pure color
colorless
Color
colorless, white
Diaphaneity
transparent
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