Mineral phase
IMA name
Clinopyroxenes subgroup
Type
Class
silicate mineral
Compound type
inosilicate
Chemical composition
Formula
$AB.[SiO_3]_2$ with $A = Na, Ca, Fe^{2+}, Mn^{2+}$ and/or $Mg$, and $B = Fe^{2+}, Mn^{2+}, Mg, Al, Zn, Ti, Cr, V$ and/or $Sc$)
Chemical formula
(Na,Ca,Fe2+,Mn2+,Mg)(Fe2+,Mn2+,Mg,Al,Zn,Ti,Cr,V,Sc)Si2O6
Elemental formula
(Na)0-1 (Ca)0-1 (Fe2+)0-1 (Mn2+)0-0.5 (Mg)0-1 (Al)0-1 (Zn)0-1 (Ti)0-1 (Cr)0-1 (V)0-1 (Sc)0-1 Si2 O6
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Na$ Sodium element 0 - 1 constituent element main
$Ca$ Calcium element 0 - 1 constituent element main
$Fe^{2+}$ Iron(II) cation element 0 - 1 constituent element main
$Mn^{2+}$ Manganese(II) cation element 0 - 0.5 constituent element main
$Mg$ Magnesium element 0 - 1 constituent element main
$Al$ Aluminium element 0 - 1 constituent element main
$Zn$ Zinc element 0 - 1 constituent element main
$Ti$ Titanium element 0 - 1 constituent element main
$Cr$ Chromium element 0 - 1 constituent element main
$V$ Vanadium element 0 - 1 constituent element main
$Sc$ Scandium element 0 - 1 constituent element main
$Si$ Silicon element 2 constituent element main
$O$ Oxygen element 6 constituent element main
Composition comments
Common impurities: $K, Co, Ni
Oxides
Formula $Na_{2}O$ $CaO$ $FeO$ $MnO$ $MgO$ $Fe_{2}O_{3}$ $Al_{2}O_{3}$ $ZnO$ $TiO_{2}$ $Cr_{2}O_{3}$ $V_{2}O_{5}$ $Sc_{2}O_{3}$ $SiO_{2}$
Mass fraction (%)

Strunz

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

Dana

Major class
silicates (VIII)
Class
inosilicate single-width unbranched chains, w=1 (65)
Type
with chains P=2 (65.01)
Group
N/A (N/A)
End-members
Members
  • P2/c clinopyroxenes: Clinoenstatite, Clinferrosilite, Kanoite, Pigeonite (Na = 0, Ca = 0-0.4 (Pigeonite))
  • C2/c Ca-Clinopyroxenes: Diopside, Hedenbergite, Augite, Johannsenite, Petudunnite, Esseneite, Davisite (Ca = 0.5-1, Na = 0-0.3 (Augite))
  • C2/c Ca,Na-Clinopyroxenes: Omphacite, Aegirine-Augite (Na = 0.1-0.9, Ca = 0.5-0.9)
  • C2/c Na-Clinopyroxenes: Jadeite, Aegirine, Namansilite, Kosmochlor, Natalyite, Jervisite (Na = 0.7-1, Ca = 0-0.3 (Jervisite))
Phase type
crystalline
Crystal system
various
Crystal class
various
Crystal class symbol
various
Crystal spacegroup
various
State NTP
solid
Refringence type
various
Refringence sign
positive or negative
Pure color
various
Color
various
Diaphaneity
transparent to opaque
Luster
various
Links