Class

silicate mineral

Compound type

phyllosilicate

Composition comments

Composition form Anceau 1992

Chemical functions

	Function	Number
	$(OH)^-$	8

Chemical bonds

	Bond	Number
	$O^--H$	1

Oxides

Formula	$SiO_{2}$	$Al_{2}O_{3}$	$MgO$	$H_{2}O$
Mass fraction (%)	33.58	37.99	15.02	13.41

Oxides comments

Oxides composition recalculated from atomic composition

Strunz

Class

silicates (09)

Division

phyllosilicate (09.E)

Family

with mica sheets, composed of tetrahedral and octahedral nets (09.EC)

Code

09.EC.55

Dana

Major class

silicates (VIII)

Class

phyllosilicate sheets of six-membered rings (71)

Type

interlayered 1:1, 2:1, and octahedra (71.04)

Group

Chlorite group (Tri-Dioctahedral) (71.04.01)

Code

71.04.01.01

Phase type

crystalline

Crystal system

monoclinic

Crystal class

prismatic

Crystal class symbol

2/m (C2h)

Crystal spacegroup

C2/m

Texture

polycrystalline

Molar mass

537.0 $g/mol$

Density

N/A $g/cm^3$

Refringence type

biaxial

Refringence sign

positive

Birefringence

0.0120-0.0180

Refraction index $n_{\alpha}$

1.56-1.578

Refraction index $n_{\beta}$

1.566-1.582

Refraction index $n_{\gamma}$

1.572-1.596

Dispersion V

Dispersion r > v

Color

White, Greenish white, Yellowish white

Luster

N/A