Feldspar

Table of contents

1 Pronunciation 2 Etymology 3 noun 4 Varieties 4.1 Potassium feldspars 4.2 Plagioclase feldspars 5 Adjective 6 Related words

Pronunciation

feld' spär, fel' spär

Etymology

Feld, field (from Middle High German veld, from Old High German feld) + Spath, spar

noun

1. A large group of rock-forming minerals that, together, make up about 60% of the earth's outer crust. The feldspars are all aluminum silicates of the alkali metals sodium, potassium, calcium and barium. Feldspars are the principal constituents of igneous and plutonic rocks.

Varieties

Potassium feldspars

1. Orthoclase
2. Microcline

Plagioclase feldspars

1. Albite
2. Oligoclase
3. Andesine
4. Labradorite
5. Bytownite
6. Anorthite

Adjective

1. Feldspathic: Containing feldspar.
2. Feldspathoid: Resembling a feldspar. Also another mineral group.

Related words

See Rock, Mineral, Granite