Stishovite | SSHADE

Mineral phase

IMA name: Stishovite

Class: non-silicate mineral
Compound type: oxide-hydroxide

Chemical composition

Formula: $SiO_2$
Chemical formula: SiO2
Elemental formula: Si O2
Isotope mixture type: terrestrial abundance

	Formula	Name	Family	Number min-max	Isotope mole fraction	State	Relevance
	$Si$	Silicon	element	1		constituent element	main
	$O$	Oxygen	element	2		constituent element	main

Chemical functions and bonds

Chemical bonds

	Bond	Number
	$\geq Si-O-$	6

Oxides composition

Oxides

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

Classifications

Strunz

Class: oxides - hydroxides - arsenites (04)
Division: metal:oxygen = 1:2 and similar (04.D)
Family: with small cations: Silica family (04.DA)
Code: 04.DA.40

Dana

Major class: oxides and hydroxides (III)
Class: simple oxides (04)
Type: with a cation charge of 4+ (A++++O2) (04.04)
Group: Rutile group (Tetragonal: P4/mnm) (04.04.01)
Code: 04.04.01.09

Crystallography

Phase type: crystalline
Crystal system: tetragonal
Crystal class: ditetragonal-dipyramidal
Crystal class symbol: 4/mmm (D4h)
Crystal spacegroup: P4(2)/mnm

Physical properties

Molar mass: 60.08 $g/mol$
Density: 4.35 (calc. 4.287) $g/cm^3$

Thermodynamical properties

State NTP

metastable solid - other solid

Phase transitions

Phase transition type	Other phases	Temperature - Pressure
solid-solid	Coesite (metastable below 1.9 GPa)	metastable below 7.9 GPa at room T, below 11 GPa at 1400°C

Phase transitions comments

the stable phase at NTP is

α - Q u a r t z

$\alpha-Quartz$

Optical properties

Refringence type: uniaxial
Refringence sign: positive
Birefringence: 0.027
Refraction index $n_o$ (w): 1.799 - 1.800
Refraction index $n_e$ (e): 1.826 - 1.845
Pure color: colorless
Color: colorless
Diaphaneity: transparent to translucent
Luster: vitreous

Links and Publications

Links