Formula	Name	Family	Number min-max	Isotope mole fraction	State	Relevance
	$Ca$	Calcium	element	1		constituent element	main
	$Fe^{2+}$	Iron(II) cation	element	1		constituent element	main
	$Si$	Silicon	element	2		constituent element	main
	$O$	Oxygen	element	6		constituent element	main

Composition comments

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

Oxides

Formula	$CaO$	$FeO$	$SiO_{2}$
Mass fraction (%)	22.6	28.96	48.44

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.02

Phase type

crystalline

Crystal system

monoclinic

Crystal class

prismatic

Crystal class symbol

2/m (C2h)

Crystal spacegroup

C2/c

Refringence type

biaxial

Refringence sign

positive

Birefringence

0.0180 - 0.0290

Refraction index $n_{\alpha}$

1.699 - 1.739

Refraction index $n_{\beta}$

1.705 - 1.745

Refraction index $n_{\gamma}$

1.728 - 1.757

Dispersion V

distinct to strong, r>v

Pure color

green

Color

brownish green, gray green, grayish black, dark green, black

Diaphaneity

transparent to opaque

Luster

vitreous

Links

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