Coombsite

Overview

K(Mn+2,Fe+2,Mg)13(Si,Al)18O42(OH)14
Fluorescence: none	Barely Detectable Radiation	Magnetic: no

Description

Physical Properties

Property	Value
Density	3 g/cc
Hardness - Mohs	Coombsite - -  10 Diamond 9 Carborundum 8 Topaz 7 Quartz 6 Orthoclase 5 Apatite 4 Fluorite 3 Calcite 2 Gypsum 1 Talc
Color	brown
Streak	brownish yellow

Crystal Properties

Property	Value
Crystal structure	trigonal - pyramidal
Cleavage	good
Tenacity	-
Fracture	-
Luster	vitreous, glassy

Similar Minerals

Dana Number : 74.01.04.02

Class: 74

Group: 74.01

Subgroup: 74.01.04 - zussmanite

Dana Number	Mineral Name	Formula
74.01.04.01	zussmanite	K(Fe+2,Mg,Mn)13(AlSi17O42)(OH)14
74.01.04.02	coombsite	K(Mn+2,Fe+2,Mg)13(Si,Al)18O42(OH)14

Nickel-Strunz Number : 09.EG.35

Group : 09

Subgroup : EG

Nickel-Strunz Number	Mineral Name	Formula
09.EG.35	coombsite	K(Mn+2,Fe+2,Mg)13(Si,Al)18O42(OH)14
09.EG.35	zussmanite	K(Fe+2,Mg,Mn)13(AlSi17O42)(OH)14

Specimens

Localities

Uses