IMA Code

Clg

	Formula	Name	Family	Number min-max	Isotope mole fraction	State	Relevance
	$Mg^{2+}$	Magnesium(II) cation	element	10		constituent cation	main
	$Fe^{3+}$	Iron(III) cation	element	2		constituent cation	main
	$(CO_3)^{2-}$	Carbonate anion	chemical function	1		anionic radical	main
	$(OH)^-$	Hydroxide anion	chemical function	24		anionic radical	main
	$H_2O$	Water	molecule	2		hydration	main

Chemical functions

	Function	Number
	$(CO_3)^{2-}$	1
	$(OH)^-$	24
	$R-OH$	2

Chemical bonds

	Bond	Number
	$\cdot Mg^{2+} \cdot O^{-}-$	20
	$\cdot (\cdot) Fe^{3+} \cdot O^{-}-$	6
	$-O-H$	2
	$\dddot - \dddot - C \dddot - O^{-2/3}$	3
	$O^--H$	1

Oxides

Formula	$MgO$	$Fe_{2}O_{3}$	$H_{2}O$	$CO_{2}$
Mass fraction (%)	46.92	18.59	29.36	5.12

Strunz

Class

carbonates - nitrates (05)

Division

carbonates with additional anions, with H2O (05.D)

Family

with medium-sized cations (05.DA)

Code

05.DA.55

Dana

Major class

carbonates, nitrates, borates (V)

Class

carbonates - hydroxyl or halogen (16b)

Type

-unclassified- (16b.07)

Group

-Coalingite- group (16b.07.06)

Code

16b.07.06.01

Phase type

crystalline

Crystal system

trigonal

Crystal class

dihexagonal-dipyramidal

Crystal class symbol

-3m (D3d)

Crystal spacegroup

R-3c

Refringence type

uniaxial

Refringence sign

negative

Birefringence

0.0280 - 0.0450

Refraction index $n_o$ (w)

1.588 - 1.635

Refraction index $n_e$ (e)

1.56 - 1.59

Pure color

brown

Color

bronze brown, light brown, reddish brown

Luster

resinous

Links

• MinDAT: Coalingite
• WebMineral: Coalingite