Class

silicate mineral

Compound type

inosilicate

	Formula	Name	Family	Number min-max	Isotope mole fraction	State	Relevance
	$Ca$	Calcium	element	1		constituent element	main
	$Mg$	Magnesium	element	1		constituent element	main
	$Si$	Silicon	element	2		constituent element	main
	$O$	Oxygen	element	6		constituent element	main

Composition comments

Diopside name used for Ca = 90-100%, Mg = 50-100%, Fe = 1-Mg = 50-0%

Oxides

Formula	$CaO$	$MgO$	$SiO_{2}$
Mass fraction (%)	25.9	18.61	55.49

Strunz

Class

silicates (09)

Division

inosilicate (09.D)

Family

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

Code

09.DA.15

Dana

Major class

silicates (VIII)

Class

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

Type

with chains P=2 (65.01)

Group

C2/c clinopyroxenes (Ca clinopyroxenes) (65.01.03a)

Code

65.01.03a.01

Phase type

crystalline

Crystal system

monoclinic

Crystal class

prismatic

Crystal class symbol

2/m (C2h)

Crystal spacegroup

C2/c

Texture

polycrystalline

Molar mass

216.55 $g/mol$

Density

3.25 - 3.55 $g/cm^3$

Refringence type

biaxial

Refringence sign

positive

Birefringence

0.0290 - 0.0300

Refraction index $n_{\alpha}$

1.663 - 1.699

Refraction index $n_{\beta}$

1.671 - 1.705

Refraction index $n_{\gamma}$

1.693 - 1.728

Dispersion V

weak to distinct, r>v

Color

colorless, blue, brown, green, gray

Diaphaneity

transparent to translucent

Luster

vitreous