Secondary names

Manganese calcium carbonate; Mn-Ca carbonate; Kutnahorite

IMA Code

Kut

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

Composition comments

$Mg^{2+}$ and $Fe^{2+}$ commonly substitute for $Mn^{2+}$, with the manganese content varying from 38% to 84%, so the formula $Ca(Mn^{2+},Mg,Fe^{2+})(CO_3)_2$ better represents the species. Typical chemical formula: $CaMn^{2+}_{0.6}Mg_{0.3}Fe^{2+}_{0.1}(CO_3)_2$

Chemical functions

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

Chemical bonds

	Bond	Number
	$\cdot Ca^{2+} \cdot O^{-}-$	1
	$\cdot Mn^{2+} \cdot O^{-}-$	1
	$\dddot - \dddot - C \dddot - O^{-2/3}$	3

Oxides

Formula	$CaO$	$MnO$	$MgO$	$FeO$	$CO_{2}$
Mass fraction (%)	27.23	20.27	5.87	3.49	42.74

Oxides comments

oxydes composition corresponding to the typical chemical formula

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.10

Dana

Major class

carbonates, nitrates, borates (V)

Class

anhydrous carbonates (14)

Type

with compound formula A+B++(CO3)2 (14.02)

Group

Dolomite group (Trigonal: R-3) (14.02.01)

Code

14.02.01.03

Phase type

crystalline

Crystal system

trigonal

Crystal class

rhombohedral

Crystal class symbol

-3 (S6)

Crystal spacegroup

R-3

Refringence type

uniaxial

Refringence sign

negative

Birefringence

0.1920

Refraction index $n_o$ (w)

1.727

Refraction index $n_e$ (e)

1.535

Pure color

colorless

Color

white, light yellow, light pink

Diaphaneity

translucent

Luster

vitreous

Links

• MinDAT: Kutnohorite
• WebMineral: Kutnohorite
• Wikipedia: Kutnohorite