Class

silicate mineral

Compound type

tektosilicate

Comments

mostly Si Tetrahedral Frameworks SiO2 with [4] coordinated Si, except Stishovite

Chemical bonds

	Bond	Number
	$\geq Si-O-$	4

Oxides

Formula	$SiO_{2}$
Mass fraction (%)	100.0

Strunz

Class

oxides - hydroxides - arsenites (04)

Division

metal:oxygen = 1:2 and similar (04.D)

Family

with small cations: Silica family (04.DA)

Dana

Major class

silicates (VIII)

Class

tectosilicate Si tetrahedral frameworks (75)

Type

SiO2 with [4] coordinated Si (75.01)

Group

N/A (N/A)

Phase type

crystalline

Crystal system

various

Crystal class

various

Crystal class symbol

various

Crystal spacegroup

various

Composition order

ordered

Molar mass

60.08 $g/mol$

Density

2.25 - 4.35 $g/cm^3$

Refringence type

various

Birefringence

0.003 - 0.027

Refraction index $n_{\alpha}$

1.468 - 1.800

Refraction index $n_{\beta}$

1.470 - 1.845

Refraction index $n_{\gamma}$

1.474 - 1.599

Dispersion V

none

Color

colorless, blue-gay, brown, violet, gray, yellow

Diaphaneity

transparent to translucent

Luster

vitreous