Composition:

Molecular Weight = 263.02 gm

 Sodium     8.30 %  Na   11.19 % Na₂O

 Calcium    0.76 %  Ca    1.07 % CaO

 Aluminum  10.77 %  Al   20.35 % Al₂O₃

 Silicon   31.50 %  Si   67.39 % SiO₂

 Oxygen    48.66 %  O

          ______        ______ 

          100.00 %      100.00 % = TOTAL OXIDE

Empirical Formula:

Na_0.95Ca_0.05Al_1.05Si_2.95O₈

Environment:

Magmatic and pegmatitic rocks.

IMA Status:

Valid Species (Pre-IMA) 1815

Locality:

USA, VA, Amelia. Madagascar, Bourg d'Oisans and Isere, France, Switzerland.

Name Origin:

From the Latin, albus, in allusion to the common color.

Synonym:

Ab100

An0

Clevelandite

Comments:  Albite crystal.
Location: Madagascar. Scale: 31 x 28 mm.

© Images by A. Darbellay

Albite crystals Switzerland  Scale: 9 x 5.5 cm.

Cell Dimensions:

a = 8.144, b = 12.787, c = 7.16, Z = 4; alpha = 94.266°, beta = 116.583°, gamma = 87.667° V = 664.40 Den(Calc)= 2.63

Crystal System:

Triclinic - PinacoidalH-M Symbol ( 1) Space Group: C1

X Ray Diffraction:

By Intensity(I/I_o): 3.176(1), 3.211(0.3), 3.752(0.3),

Color:

White, Gray, Greenish gray, Bluish green, Gray.

Density:

2.61 - 2.63, Average = 2.62

Diaphaniety:

Transparent to translucent to subtranslucent

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Habit:

Blocky - Crystal shape tends to be equant (e.g. feldspars).

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Habit:

Striated - Parallel lines on crystal surface or cleavage face.

Hardness:

7 - Quartz

Luminescence:

None.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Data:

Biaxial (+), a=1.528-1.533, b=1.5317-1.53685, g=1.538-1.542, bire=0.0090-0.0100, 2V(Calc)=76-82, 2V(Meas)=45. Dispersion relatively weak.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.