Constituent
Name
Hectorite
IMA name
Hectorite
Class
silicate mineral
Compound type
phyllosilicate
Relevance
main - major
Arrangement
single phase
Mass fraction
1.0
Formula
$Na_{0.3}(Mg,Li)_3.Si_4O_{10}(OH)_2$
Chemical formula
Na0.3(Mg,Li)3Si4O10(OH)2
Elemental formula
(Na)0.3-0.5 (Mg)2.5-3 (Li)0-0.5 Si4 O12 H2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Na$ Sodium element 0.3 - 0.5 constituent element main
$Mg$ Magnesium element 2.5 - 3 constituent element main
$Li$ Lithium element 0 - 0.5 constituent element main
$Si$ Silicon element 4 constituent element main
$O$ Oxygen element 12 constituent element main
$H$ Hydrogen element 2 constituent element main
Composition comments
Typical formula: $Na_{0.4}(Mg_{2.7}Li_{0.3}).Si_4O_{10}(OH)_2$ - Common impurities: Ti, Al, Fe, Ca, K, Cl
Chemical functions
  Function Number
$(OH)^-$ 2
Chemical bonds
  Bond Number
$O^--H$ 1
Oxides
Formula $Na_{2}O$ $MgO$ $Li_{2}O$ $SiO_{2}$ $H_{2}O$
Mass fraction (%)

Strunz

Class
silicates (09)
Division
phyllosilicate (09.E)
Family
Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets (09.EC)
Code
09.EC.45

Dana

Major class
silicates (VIII)
Class
phyllosilicate sheets of six-membered rings (71)
Type
with 2:1 clays (71.03)
Group
Smectite group (Trioctahedral Smectites) (71.03.01b)
Code
71.03.01b.04
Phase type
crystalline
Crystal system
monoclinic
Crystal class
prismatic
Crystal class symbol
2/m (C2h)
Crystal spacegroup
C2/m
Texture
monocrystalline
Molar mass
383.25 $g/mol$
Density
2 - 3 $g/cm^3$
Refringence type
biaxial
Refringence sign
negative
Birefringence
0.030
Refraction index $n_{\alpha}$
1.49
Refraction index $n_{\beta}$
1.50
Refraction index $n_{\gamma}$
1.52
Color
white
Diaphaneity
translucent to opaque
Luster
earthy