Constituent
Name
clinochlore
IMA name
Clinochlore
Class
silicate mineral
Compound type
phyllosilicate
Constituent abundance in material
Relevance
main - major
Arrangement
single phase
Mass fraction
1.0 $\pm$ 0.01
Chemical composition
Formula
[$(Fe_^{2+}_{0.32}Fe_^{3+}_{0.09}Mg_{4.42}Cr_{0.02}Al_{1.11}Ni_{0.02})(Si_{2.81}Al_{1.19})O_{10}(OH)_8$
Chemical formula
(Mg,Fe2+)5Al(Si3Al)O10(OH)8
Elemental formula
(Fe2+)0.32-2 (Fe3+)0.09 (Mg)4.42-5.06 (Al)2.3-2 Cr0.02 Ni0.02 (Si)2.81-3.25 O18 H8
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Fe^{2+}$ Iron(II) cation element 0.32 - 2 1.0 constituent element main
$Fe^{3+}$ Iron(III) cation element 0.09 1.0 constituent element main
$Mg$ Magnesium element 4.42 - 5.06 1.0 constituent element main
$Al$ Aluminium element 2.3 - 2 1.0 constituent element main
$Cr$ Chromium element 0.02 1.0 constituent element main
$Ni$ Nickel element 0.02 1.0 constituent element main
$Si$ Silicon element 2.81 - 3.25 1.0 constituent element main
$O$ Oxygen element 18 1.0 constituent element main
$H$ Hydrogen element 8 1.0 constituent element main
Composition comments
Common impurities: Ca (replace Mg, $Fe^{2+}$) and Cr, $Fe^{3+}$ (replace Al)
Chemical functions
  Function Number
$(OH)^-$ 8
Chemical bonds
  Bond Number
$O^--H$ 1
Oxides
Formula $SiO_{2}$ $Al_{2}O_{3}$ $FeO$ $Fe_{2}O_{3}$ $MgO$ $Cr_{2}O_{3}$ $NiO$ $H_{2}O$
Mass fraction (%) 29.93 20.75 4.05 1.2 31.58 0.2 0.25 12.46
Oxides comments
for $(Mg_{3.75},Fe^{2+}_{1.25})Si_3Al_2O_10(OH)_8$ - Oxides compositions measured by Electron Micro Probe Analysis. H2O content recalculated from the structural formula.

Strunz

Class
silicates (09)
Division
phyllosilicate (09.E)
Family
Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets (09.EC)
Code
09.EC.55

Dana

Major class
silicates (VIII)
Class
phyllosilicate sheets of six-membered rings (71)
Type
interlayered 1:1, 2:1, and octahedra (71.04)
Group
Chlorite group (Tri-Dioctahedral) (71.04.01)
Code
71.04.01.04
Phase type
crystalline
Crystal system
monoclinic
Crystal class
prismatic
Crystal class symbol
2/m (C2h)
Crystal spacegroup
C2/m
Texture
polycrystalline
Molar mass
578.0 $g/mol$
Density
N/A $g/cm^3$
Refringence type
biaxial
Refringence sign
positive
Birefringence
0.005 - 0.011
Refraction index $n_{\alpha}$
1.571 - 1.588
Refraction index $n_{\beta}$
1.571 - 1.589
Refraction index $n_{\gamma}$
1.576 - 1.599
Dispersion V
r < v
Color
white, blackish green, bluish green, yellowish green, olive green, pink
Diaphaneity
transparent to translucent
Luster
N/A