Formula	Name	Family	Number min-max	Isotope mole fraction	State	Relevance
	$Fe^{2+}$	Iron(II) cation	element	2 - 3		constituent element	main
	$Fe^{3+}$	Iron(III) cation	element	0 - 1		constituent element	main
	$Mn^{2+}$	Manganese(II) cation	element	0 - 3		constituent element	main
	$Mg$	Magnesium	element	0 - 3		constituent element	main
	$Ni$	Nickel	element	0 - 3		constituent element	main
	$Si$	Silicon	element	2		constituent element	main
	$O$	Oxygen	element	9		constituent element	main
	$H$	Hydrogen	element	4		constituent element	main

Composition comments

Common substitution: Zn substituting 2+ ions, As substituting Si, Cl substituting OH - Common impurities: Al, Ca, Na, K, F

Chemical functions

	Function	Number
	$(OH)^-$	4

Chemical bonds

	Bond	Number
	$O^--H$	1

Oxides

Formula	$FeO$	$Fe_{2}O_{3}$	$MnO$	$MgO$	$NiO$	$SiO_{2}$	$H_{2}O$
Mass fraction (%)

Strunz

Class

silicates (09)

Division

phyllosilicate (09.E)

Family

with kaolinite layers composed of tetrahedral and octahedral nets (09.ED)

Code

09.ED.15

Dana

Major class

silicates (VIII)

Class

phyllosilicate sheets of six-membered rings (71)

Type

with 1:1 layers (71.01)

Group

Serpentine group (Lizardite subgroup) (71.01.02b)

End-members

• Caryopilite
• Lizardite 1T
• Nepouite
• Greenalite

Phase type

crystalline

Crystal system

various

Crystal class

various

Crystal class symbol

various

Crystal spacegroup

various

Refringence type

biaxial

Refringence sign

positive or negative

Birefringence

0.001 - 0.035

Refraction index $n_{\alpha}$

1.541 - 1.675

Refraction index $n_{\beta}$

1.565 - 1.674

Refraction index $n_{\gamma}$

1.553 - 1.674

Dispersion V

weak to medium

Pure color

various

Color

white, blue green, light yellow green, dark green, yellow, reddish brown, greenish brown, orange brown, black

Diaphaneity

transparent to opaque

Links

• Webmineral database