Anorthite

The Handbook of Mineralogy records the crystal data of anorthite as triclinic.

Evidence support: Supported by the cited evidence · one source

Evidence: Mineral Data Publishing 2001 · Institutional reference

The Handbook of Mineralogy gives a measured density for anorthite of 2.74–2.76 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 2.75 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

Anorthite is an accepted mineral species in the IMA List of Minerals, with the CNMNC-approved formula Ca(Al2Si2O8) and IMA status “grandfathered”.

• 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