Constituent Alum-(K) | SSHADE

Constituent

Name: Alum-(K)
IMA name: Alum-(K)

Class: non-silicate mineral
Compound type: sulfate

Constituent abundance in material

Relevance: main - major
Arrangement: in multi-phases
Mass fraction: 0.2 $\pm$ 0.1

Chemical composition

Formula: $KAl(SO_4)_2 \bullet 12(H_2O)$
Chemical formula: KAl(SO4)2•12(H2O)
Elemental formula: (K+) Al S2 O16 (O-)4 H24
Isotope mixture type: terrestrial abundance

	Formula	Name	Family	Number min-max	Isotope mole fraction	State	Relevance
	$K^+$	Potassium(1+) cation	element	1		constituent cation	main
	$Al$	Aluminium	element	1		constituent element	main
	$(SO_4)^{2-}$	Sulfate anion	chemical function	2		anionic radical	main
	$H_2O$	Water	molecule	12		hydration	main

Chemical functions and bonds

Chemical functions

	Function	Number	Relevance
	$(SO_4)^{2-}$	2
	$R-OH$	2	main

Chemical bonds

	Bond	Number	Relevance
	$-O-H$	2	main
	$\dddot - \dddot - \dddot - S \dddot - O^{-1/2}$	4

Oxides composition

Oxides

Formula	$K_{2}O$	$Al_{2}O_{3}$	$H_{2}O$	$SO_{3}$
Mass fraction (%)	9.93	10.75	45.57	33.75

Classifications

Strunz

Class: sulfates - chromates - molybdates - tungstates (07)
Division: sulfates (selenates, etc.) without additional anions, with H2O (07.C)
Family: with medium-sized and large cations (07.CC)
Code: 07.CC.20

Dana

Major class: sulfates, chromates, selenates (VI)
Class: hydrated acid and sulfates (29)
Type: where AB(XO4)2.x(H2O) (29.05)
Group: Alum group (29.05.05)
Code: 29.05.05.01

Phase type: crystalline

Crystallography

Crystal system: isometric (cubic)
Crystal class: diploidal
Crystal class symbol: m-3 (Th)
Crystal spacegroup: Pa-3

Physical properties

Molar mass: 474.39 $g/mol$
Density: 1.76 $g/cm^3$

Optical properties

Refringence type: isotropic
Refraction index $n_{\alpha}$: 1.453
Color: colorless, white
Diaphaneity: transparent
Luster: vitreous