Formula	Name	Family	Number min-max	Isotope mole fraction	State	Relevance
	$Fe^{2+}$	Iron(II) cation	element	2		constituent element	main
	$Si$	Silicon	element	2		constituent element	main
	$O$	Oxygen	element	6		constituent element	main

Composition comments

Common substitution: Mg, $Mn^{2+}$ - Common impurities: Al, $Fe^{3+}$, Ca, Na, K, Co, Ni, Mn, Ti, Cr

Oxides

Formula	$FeO$	$SiO_{2}$
Mass fraction (%)	54.45	45.55

Strunz

Class

silicates (09)

Division

inosilicate (09.D)

Family

with 2-periodic single chains, Si2O6; pyroxene family (09.DA)

Code

09.DA.05

Dana

Major class

silicates (VIII)

Class

inosilicate single-width unbranched chains, w=1 (65)

Type

with chains P=2 (65.01)

Group

Orthopyroxenes (65.01.02)

Code

65.01.02.02

Phase type

crystalline

Crystal system

orthorhombic

Crystal class

dipyramidal

Crystal class symbol

mmm (D2h)

Crystal spacegroup

Pbca

Refringence type

biaxial

Refringence sign

positive

Birefringence

0.016 - 0.021

Refraction index $n_{\alpha}$

1.710 - 1.767

Refraction index $n_{\beta}$

1.723 - 1.770

Refraction index $n_{\gamma}$

1.726 - 1.788

Dispersion V

strong (r < v)

Pure color

colorless

Color

colorless, green

Diaphaneity

translucent

Luster

vitreous

Links

• Wikipedia
• Webmineral database
• Mindat
• Handbook of Mineralogy (Min. Soc. Am)