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LITHOEN

Mineral

Diopside

A calcium–magnesium clinopyroxene: a single-chain silicate and one of the principal minerals of the mantle and of calcium-rich metamorphic rocks.

Pale green prismatic diopside crystals on a rock matrix.
Diopside from Aosta, Italy. Diopside is a calcium–magnesium clinopyroxene: a single-chain silicate, and one of the principal minerals of the mantle and of calcium-rich metamorphic rocks. Locality: Aosta, Italy.

Didier Descouens, CC BY-SA 3.0 · CC-BY-SA-3.0 · source · Derivative: Downscaled to 1000 px wide by the Wikimedia thumbnail service; no cropping, no colour or content alteration.

Classification

formula
CaMgSi2O6
ima status
approved
crystal system
monoclinic

How this record is known

3
Settled consensus
Cited as the accepted position of the discipline.

3 of 3 claims on this page cite at least one registered source. Counts describe how each statement is known, not how likely it is to be true.

What Lithoen records

Each claim states how it is known and cites its evidence.

EstablishedMonoclinic

The Handbook of Mineralogy records the crystal data of diopside as monoclinic.

Evidence support: Supported by the cited evidence one source

Evidence: Mineral Data Publishing 2001 Institutional reference

Established3.3 g/cm3

The Handbook of Mineralogy gives a measured density for diopside of 3.3 g/cm3.

  • precision note: A reference value from a compiled data sheet, and for several species the midpoint or single figure of a published range.
  • method: Compiled from published measurements; Lithoen holds no measurement of its own.

Evidence support: Supported by the cited evidence one source

Evidence: Mineral Data Publishing 2001 Institutional reference

EstablishedCaMgSi2O6

Diopside is an accepted mineral species in the IMA List of Minerals, with the CNMNC-approved formula CaMgSi2O6 and IMA status “approved”.

  • definition basis: IMA List of Minerals, September 2026 update, which is the authority on mineral species status.
  • precision note: An approved formula is an idealised composition; natural crystals of most species depart from it through substitution.

Evidence support: Supported by the cited evidence one source

Evidence: Commission on New Minerals, Nomenclature and Classification, International Mineralogical Association 2026 Primary authority

In the knowledge graph

  • Diopside has essential constituent Calcium
  • Diopside preferentially receives Chromium
  • Diopside member of Pyroxene
  • Diopside has essential constituent Magnesium
  • Diopside has essential constituent Oxygen
  • Diopside has essential constituent Silicon

Figures

Five groups of triangles representing silicon-oxygen tetrahedra, arranged as isolated units, a single chain, a double chain, a sheet and a framework, each labelled with example minerals and a silicon-to-oxygen ratio.
SchematicHow silicon–oxygen tetrahedra link, and what each arrangement produces. Sharing more oxygens between tetrahedra lowers the oxygen content relative to silicon, from 1:4 in isolated tetrahedra to 1:2 in a framework — which is why the structural class can be read from the formula.
Full description of this figure

The diagram sets out five structural classes of silicate. Isolated tetrahedra share no oxygens and give Si:O of 1:4, as in olivine and garnet. Single chains share two oxygens per tetrahedron, giving 1:3, as in pyroxene. Double chains share two and three alternately, giving 4:11, as in amphibole. Sheets share three, giving 2:5, as in mica and clay. Frameworks share all four, giving 1:2, as in quartz and feldspar. Moving left to right is a progression of increasing polymerisation.

Original Lithoen diagram · LITHOEN-ORIGINAL

Record last updated 2026-09-06. Corrections follow the published corrections policy; superseded claims are retained, never silently edited.