Class

non-silicate mineral

Compound type

carbonate

Comments

impurity in Portlandite matter
Equivalent Space Group: Pmcn (62)

	Formula	Name	Family	Number min-max	Isotope mole fraction	State	Relevance
	$Ca^{2+}$	Calcium cation	element	1		constituent cation	main
	$(CO_3)^{2-}$	Carbonate anion	chemical function	1		anionic radical	main

Chemical functions

	Function	Number
	$(CO_3)^{2-}$	1

Chemical bonds

	Bond	Number
	$\cdot Ca^{2+} \cdot O^{-}-$	2
	$\dddot - \dddot - C \dddot - O^{-2/3}$	3

Oxides

Formula	$CaO$	$CO_{2}$
Mass fraction (%)	56.03	43.97

Strunz

Class

carbonates - nitrates (05)

Division

carbonates without additional anions, without H2O (05.A)

Family

Alkali-earth (and other M2+) carbonates (05.AB)

Code

05.AB.15

Dana

Major class

carbonates, nitrates, borates (V)

Class

anhydrous carbonates (14)

Type

with simple formula A+CO3 (14.01)

Group

Aragonite group (Orthorhombic: Pmcn) (14.01.03)

Code

14.01.03.01

Phase type

crystalline

Crystal system

orthorhombic

Crystal class

dipyramidal

Crystal class symbol

mmm (D2h)

Crystal spacegroup

Pnma

Molar mass

100.09 $g/mol$

Density

2.93 $g/cm^3$

Refringence type

biaxial

Refringence sign

negative

Birefringence

0.156

Refraction index $n_{\alpha}$

1.529 - 1.53

Refraction index $n_{\beta}$

1.68 - 1.682

Refraction index $n_{\gamma}$

1.685-1.686

Color

colorless, white, grey, yellow

Diaphaneity

transparent to translucent

Luster

vitreous