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LITHOEN

Mineral group

Alkali feldspar

The potassium- and sodium-rich feldspars, including microcline, orthoclase and sanidine — one composition, three structural states, three species.

Classification

group kind
series

How this record is known

1
Settled consensus
Cited as the accepted position of the discipline.

1 of 1 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.

EstablishedOne composition, three structural states, three species.

Microcline, orthoclase and sanidine share one approved formula, K(AlSi3O8), and are three distinct accepted species. What separates them is the ordering of aluminium and silicon over the tetrahedral sites — structure, not composition.

  • precision note: That the three share a formula is read directly from the IMA list; the ordering explanation is the standard structural account of why they are separate species.

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 Corrections follow the published corrections policy; superseded claims are retained, never silently edited.