Diagnostic Features

Hardness: 6
Streak: White to pink
Luster: Nonmetallic
Specific Gravity: 2.6
Cleavage: Present  (2 directions)
Fracture: None



 your text.
Identification Tips

1.  The mainly dark orange to salmon color of orthoclase is characteristic. It is a principal constituent of granites, gneisses and pegmatites.
2.  Orthoclase commonly occurs with quartz and mica and is easily distinguishable by its color and cleavage.


Orthoclase

[Potassium Feldspar]
Photographs by Michael Amadeus Klimetz
Microcline

Catamarca Province
ARGENTINA
Microcline

Middletown
CONNECTICUT
Microcline


Estes Pegmatite
West Baldwin

Cumberland County
MAINE
Adularia


Canton Graubunden
SWITZERLAND
Adularia


Canton Graubunden
SWITZERLAND
Adularia


Canton Graubunden
SWITZERLAND
Adularia


Canton Graubunden
SWITZERLAND
Microcline

Pikes Peak

El Paso County
COLORADO
Microcline

Pikes Peak

El Paso County
COLORADO
Microcline

Parker Mountain Mine
Center Strafford

Strafford County
NEW HAMPSHIRE
Microcline

Parker Mountain Mine
Center Strafford

Strafford County
NEW HAMPSHIRE
Microcline
[Crystal Plate Illustrating Characteristic Orthogonal Cleavage Surfaces andTopped with Spessartine Garnet]

Shigar Valley

Northern Territories
PAKISTAN
Microcline
[Crystal Plate Illustrating Characteristic Orthogonal Cleavage Surfaces and Topped with Spessartine Garnet]

Shigar Valley

Northern Territories
PAKISTAN
Microcline
[Crystal Plate Illustrating Characteristic Orthogonal Cleavage Surfaces andTopped with Spessartine Garnet]

Shigar Valley

Northern Territories
PAKISTAN
Adularia
Blocky Transparent Crystals with Clinochlore on Matrix

Mirošov
Žďár nad Sázavou District

Vysočina Region
CZECH REPUBLIC
Amazonite
Terminated Crystal Tip

Teller County
COLORADO
Amazonite
Terminated Crystal Tip

Teller County
COLORADO
Amazonite
Terminated Crystal Tip

Teller County
COLORADO
Microcline
Cleaved Partial Crystal

Minas Gerais
BRAZIL
Microcline
Cleaved Crystals with Biotite and Quartz

West Side Excavation

Manhattan County
NEW YORK
Microcline
Terminated Compound Crystal

Crystal Peak

Teller County
COLORADO
Microcline
Terminated Compound Crystal

Crystal Peak

Teller County
COLORADO