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LITHOEN

Mineral

Orthoclase

A potassium feldspar of intermediate structural order — the same composition as microcline and sanidine, distinguished from them by how aluminium and silicon are arranged.

Classification

formula
K(AlSi3O8)
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 orthoclase as monoclinic.

Evidence support: Supported by the cited evidence one source

Evidence: Mineral Data Publishing 2001 Institutional reference

Established2.55–2.63 g/cm3

The Handbook of Mineralogy gives a measured density for orthoclase of 2.55–2.63 g/cm3.

  • method: Compiled from published measurements; Lithoen holds no measurement of its own.
  • precision note: The data sheet gives a range of measured densities, not a single value. An earlier version of this claim published 2.59 g/cm3 — approximately the midpoint — and attributed it to the Handbook, which states no representative value. Lithoen now publishes the range the source gives. Where the Handbook does state a single measured density, as for quartz, the corpus carries that value as a scalar.

Evidence support: Supported by the cited evidence one source

Evidence: Mineral Data Publishing 2001 Institutional reference

EstablishedK(AlSi3O8)

Orthoclase is an accepted mineral species in the IMA List of Minerals, with the CNMNC-approved formula K(AlSi3O8) 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

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 Corrections follow the published corrections policy; superseded claims are retained, never silently edited.