Mineral phase
IMA name
Clinopyroxenes subgroup
Class
silicate mineral
Compound type
inosilicate
Formula
AB.[SiO3]2 with A=Na,Ca,Fe2+,Mn2+ and/or Mg, and B=Fe2+,Mn2+,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
Fe2+ Iron(II) cation element 0 - 1 constituent element main
Mn2+ 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 Na2O CaO FeO MnO MgO Fe2O3 Al2O3 ZnO TiO2 Cr2O3 V2O5 Sc2O3 SiO2
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