Mineral 1.0Test your knowledge of specific minerals

M
E
N
U
« Home | Browse Minerals | QuizzesMinerals by letter: All | K | G | O | A | H | T | P | C | Q | N | Z | S | E | W | M | B | F | D | L
Minerals by class: Silicates | Halides | Carbonates | Sulfates | Oxides | Phosphates | Hydroxides | Native elements | Sulfides
Silicate Subclasses: Nesosilicates | Pyroxenes | Amphiboles | Frameworks | Sorosilicates | Cyclosilicates | Phyllosilicates
  

« Back to mineral listing

P
L
A
G
I
O
C
L
A
S
E

Click for expanded view








Plagioclase  (Anothite (Ca), Albite (Na))CaAl2Si2O8

Class: Silicate
Subclass: Framework
Hardness: 6 - 6.5
Streak: White
Lustre: Vitreous
Colours: White and gray

  Crystal System: Triclinic
Cleavage: Good
Magnetism: None
Reaction with HCl: Weak

Identification in hand sample:
Parallel striations and white-gray colour separates this mineral from orthoclase (Kspar).

Associations:
Most abundant mineral in the Earth's crust.

Industrial / ecomonic uses:
Concrete, filler, sand, gravel, etc.

Comments:
Calcium-rich plag is called Anorthite. Sodium-rich plag is called Albite. Twinning occurs.

  

Inaccurate data? Better photos? .