ORTHOCLASE

noun

15 Scrabble

16 WWF

O 1

R 1

T 1

H 4

O 1

C 3

L 1

A 1

S 1

E 1

Definition

Potassium aluminum silicate, KAlSi3O8, a common feldspar of igneous, plutonic, and metamorphic rocks. Orthoclase is the main feldspar of pegmatite occurrences, where it is most commonly flesh-colored. Orthoclase is used in the ceramic and glass industries and as a decorative gravel.