Secondary names

Potassium calcium carbonate; K-Ca carbonate

IMA Code

Fch

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

Oxides

Formula	$K_{2}O$	$CaO$	$CO_{2}$
Mass fraction (%)	39.53	23.53	36.94

Strunz

Class

carbonates - nitrates (05)

Division

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

Family

Alkali and alkali-earth carbonates (05.AC)

Code

05.AC.20

Dana

Major class

carbonates, nitrates, borates (V)

Class

anhydrous carbonates (14)

Type

with Compound Formula A+2B++(CO3)2 (14.03)

Group

Fairchildite series (14.03.03)

Code

14.03.03.01

Polymorphs

• Bütschliite (stable low temperature phase)

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

0.0540

Refraction index $n_o$ (w)

1.532

Refraction index $n_e$ (e)

1.478

Pure color

colorless

Color

colorless

Diaphaneity

transparent

Luster

vitreous

Links

• MinDAT: Fairchildite
• WebMineral: Fairchildite