Formula	Name	Family	Number min-max	Isotope mole fraction	State	Relevance
	$Mn^{2+}$	Manganese(II) cation	element	0 - 1		constituent element	main
	$Mg$	Magnesium	element	1 - 2		constituent element	main
	$Si$	Silicon	element	2		constituent element	main
	$O$	Oxygen	element	6		constituent element	main

Composition comments

Common substitution: $Fe^{2+}$ - Common impurities: Al, $Fe^{3+}$, Ca, Na

Oxides

Formula	$MnO$	$MgO$	$SiO_{2}$
Mass fraction (%)	23.78	22.52	53.71

Oxides comments

for $Mn_{0.5}Mg_{1.5}.[SiO_3]_2$ (x=0.5)

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

65.01.02.03

Phase type

crystalline

Crystal system

orthorhombic

Crystal class

dipyramidal

Crystal class symbol

mmm (D2h)

Crystal spacegroup

Pbca

Refringence type

biaxial

Refringence sign

negative

Birefringence

0.015

Refraction index $n_{\alpha}$

1.677

Refraction index $n_{\beta}$

1.684

Refraction index $n_{\gamma}$

1.692

Dispersion V

weak

Pure color

yellow

Color

yellow-orange

Diaphaneity

transparent to translucent

Luster

vitreous

Links

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