Materials

Feldspar

Mineral Group

Citation Formats

General Reference

Earth and Environment Atlas. "Feldspar." Accessed August 30, 2026. https://earth.interactiveatlas.org/materials/feldspar.

APA Style

Earth and Environment Atlas. (n.d.). Feldspar. Retrieved August 30, 2026, from https://earth.interactiveatlas.org/materials/feldspar

BibTeX

@misc{earthandenvironmentatlas-feldspar,
  author = {Earth and Environment Atlas},
  title = {Feldspar},
  year = {2026},
  url = {https://earth.interactiveatlas.org/materials/feldspar},
  note = {Accessed August 30, 2026}
}

A group of rock-forming silicate minerals, the single most abundant mineral group in the Earth's crust, and the source of the pale crystals that give granite its speckled look.

Facts

Kind

Mineral 1

Formation Class

Framework silicate, the most abundant mineral group in the Earth's crust 1

Chemical Formula

KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8 (end-member series) 2

Hardness (Mohs)

6 1

Standard reference value for the feldspar group generally; individual species vary slightly.

Cross-Tradition Connections

In Discipline

Mineralogy

Source Mineral (Wikipedia)

Sources

1. Mineral (Wikipedia)

Wikimedia FoundationView the Source

2. Feldspar (Wikipedia)

Wikimedia FoundationComposition section

Quote, Composition section

orthoclase endmember KAlSi3O8, albite endmember NaAlSi3O8, anorthite endmember CaAl2Si2O8

View the Source

Comments (0)

No comments yet. Be the first to share a thought.

Reader Challenges (0 open reader challenges)

No disputes yet. Spotted an error or a better source? Open the first one.

View At A Past Year

The atlas records no dated fact of its own for this entry, so there is no other year to choose.

Switch Atlas

The Inner World

The Civil World

The Natural World