Secondary names

K2Ca(CO3)2

10.0

	Formula	Name	Family	Number min-max	Mole fraction	Isotope mole fraction	State	Relevance
	$K^+$	Potassium(1+) cation	element	2	0.4	1	constituent cation	main
	$Ca^{2+}$	Calcium cation	element	1	0.2	1	constituent cation	main
	$(CO_3)^{2-}$	Carbonate anion	chemical function	2	0.4	1	anionic radical	main

Chemical functions

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

Chemical bonds

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

Class

normal salts (07)

Type

double normal salts (07.02)

Polymorphs

• alpha Dipotassium calcium carbonate

Equivalent mineral

Fairchildite

Phase name

$\beta-K_2Ca(CO_3)_2$

Phase type

crystalline

Crystal system

hexagonal

Crystal class

dihexagonal-dipyramidal

Crystal class symbol

6/mmm (D6h)

Crystal spacegroup

P6(3)/mmc

Refringence type

uniaxial

Refringence sign

negative

Birefringence

0.1035

Refraction index $n_{\alpha}$

1.533

Refraction index $n_{\beta}$

1.498

Pure color

colorless

Color

colorless, white

Diaphaneity

translucent

Links

• MinDAT: Fairchildite