"The (010) plane of an orthoclase crystal." -Johannsen, 1908

Orthoclase Crystal

"The (010) plane of an orthoclase crystal." -Johannsen, 1908

"The (001) plane of an orthoclase crystal." -Johannsen, 1908

Orthoclase Crystal

"The (001) plane of an orthoclase crystal." -Johannsen, 1908

"A Carlsbad twin of orthoclase." -Johannsen, 1908

Orthoclase Twin

"A Carlsbad twin of orthoclase." -Johannsen, 1908

"A Baveno twin of orthoclase." -Johannsen, 1908

Orthoclase Twin

"A Baveno twin of orthoclase." -Johannsen, 1908