Constituent akaganeite | SSHADE

Constituent

Name: akaganeite
IMA name: Akaganeite

Class: non-silicate mineral
Compound type: oxide-hydroxide
Comments: formula given as $Fe^{3+}(O,OH,Cl)$ in Webmineral

Constituent abundance in material

Relevance: main - major
Arrangement: single phase
Mass fraction: 1.0

Chemical composition

Formula: $(Fe^{3+},Ni^{2+})_8(OH,O)_16Cl_1.25 /bullet nH2O$
Chemical formula: (Fe3+,Ni2+)8(OH,O)16Cl1.25 • nH2O
Elemental formula: (Fe3+) O H (O-)
Isotope mixture type: terrestrial abundance

	Formula	Name	Family	Number min-max	Isotope mole fraction	State	Relevance
	$Fe^{3+}$	Iron(III) cation	element	7 - 8		constituent cation	main
	$Ni^{2+}$	Nickel cation	element	0 - 1		constituent cation	main
	$(OH)^-$	Hydroxide anion	chemical function	9 - 10		anionic radical	main
	$O^{2-}$	Oxide anion	element	6 - 7		constituent anion	main
	$Cl^-$	Chloride anion	element	1.2 - 1.3		constituent anion	main

Composition comments: Ni may possibly be > 1

Chemical functions and bonds

Chemical functions

	Function	Number
	$(OH)^-$	1

Chemical bonds

	Bond	Number
	$O^--H$	1

Oxides composition

Oxides

Formula	$Fe_{2}O_{3}$	$NiO$	$H_{2}O$	$Cl$
Mass fraction (%)	79.7	3.92	11.48	6.05

Classifications

Strunz

Class: oxides - hydroxides - arsenites (04)
Division: metal:oxygen = 1:2 and similar (04.D)
Family: with large (+/- medium-sized) cations; tunnel structures (04.DK)
Code: 04.DK.05

Dana

Major class: oxides and hydroxides (III)
Class: hydroxides and oxides containing hydroxyl (06)
Type: where X+++O OH (06.01)
Group: -Akaganeite- group (06.01.06)
Code: 06.01.06.01

Phase type: crystalline

Crystallography

Crystal system: monoclinic
Crystal class: prismatic
Crystal class symbol: 2/m (C2h)
Crystal spacegroup: P2/m
Comments: Effective space group: I2/m

Physical properties

Molar mass: 761.37 $g/mol$
Density: 3.52 - 3.55 $g/cm^3$

Optical properties

Refringence type: biaxial
Refraction index $n_{\alpha}$: 1.99 - 2.19 (calc.)
Color: brown, rusty brown
Diaphaneity: transparent to opaque