Constituent
Name
Fine-grained Diopside (CAI Colony)
IMA name
Diopside
Class
silicate mineral
Compound type
inosilicate
Relevance
main - major
Arrangement
single phase
Mass fraction
1.0
Formula
$CaMg.[SiO_3]_2$
Chemical formula
CaMgSi2O6
Elemental formula
Mg0.801 Ca0.949 Si1.745 O6 Al0.439 Ti0.041 Fe0.019
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Mg$ Magnesium element 0.801 1.0 constituent element main
$Ca$ Calcium element 0.949 1.0 constituent element main
$Si$ Silicon element 1.745 1.0 constituent element main
$O$ Oxygen element 6 1.0 constituent element main
$Al$ Aluminium element 0.439 1.0 constituent element replacement
$Ti$ Titanium element 0.041 1.0 constituent element replacement
$Fe$ Iron element 0.019 1.0 constituent element replacement
Composition comments
Diopside name used for Ca = 90-100%, Mg = 50-100%, Fe = 1-Mg = 50-0%
Oxides
Formula $FeO$ $SiO_{2}$ $TiO_{2}$ $MgO$ $CaO$ $Al_{2}O_{3}$
Mass fraction (%) 0.64 48.23 1.5 14.85 24.49 10.29

Strunz

Class
silicates (09)
Division
inosilicate (09.D)
Family
with 2-periodic single chains, Si2O6; pyroxene family (09.DA)
Code
09.DA.15

Dana

Major class
silicates (VIII)
Class
inosilicate single-width unbranched chains, w=1 (65)
Type
with chains P=2 (65.01)
Group
C2/c clinopyroxenes (Ca clinopyroxenes) (65.01.03a)
Code
65.01.03a.01
Phase type
crystalline
Crystal system
monoclinic
Crystal class
prismatic
Crystal class symbol
2/m (C2h)
Crystal spacegroup
C2/c
Molar mass
217.41 $g/mol$
Density
3.25 - 3.55 $g/cm^3$
Refringence type
biaxial
Refringence sign
positive
Birefringence
0.0290 - 0.0300
Refraction index $n_{\alpha}$
1.663 - 1.699
Refraction index $n_{\beta}$
1.671 - 1.705
Refraction index $n_{\gamma}$
1.693 - 1.728
Dispersion V
weak to distinct, r>v
Color
colorless, blue, brown, green, gray
Diaphaneity
transparent to translucent
Luster
vitreous