Image credit: R. Weller, Cochise College
Uncredited images and diagrams: Scott Brande
Explore/observe features
cleavage
luster
crystal form
3D model CC4.0 BY-SA courtesy Meg Stewart
orthoclase - the pure (end-member) mineral . Feldspar is the name of a group in which the chemical compound can vary continuously (solid solution series).
(interpreting mineral chemical formulas: atoms, molecules, elements)