Montmorillonite

Overview

(Na,Ca)0.3(Al,Mg)2Si4O10(OH)2·n(H2O)
Fluorescence: none	Not Radioactive	Magnetic: no

Description

Physical Properties

Property	Value
Density	2.0-2.7 g/cc
Hardness - Mohs	Montmorillonite - 1.5-2.0  10 Diamond 9 Carborundum 8 Topaz 7 Quartz 6 Orthoclase 5 Apatite 4 Fluorite 3 Calcite 2 Gypsum 1 Talc
Color	white, gray, yellow
Streak	white

Crystal Properties

Property	Value
Crystal structure	monoclinic - prismatic
Cleavage	perfect
Tenacity	-
Fracture	earthy
Luster	earthy

Similar Minerals

Dana Number : 71.03.01a.02

Class: 71

Group: 71.03

Subgroup: 71.03.01a - smectite

Dana Number	Mineral Name	Formula
71.03.01a.02	montmorillonite	(Na,Ca)0.3(Al,Mg)2Si4O10(OH)2·n(H2O)
71.03.01a.03	nontronite	Na0.3Fe+32(Si,Al)4O10(OH)2·n(H2O)
71.03.01a.04	volkonskoite	Ca0.3(Cr+3,Mg,Fe+3)2(Si,Al)4O10(OH)2·4(H2O)

Nickel-Strunz Number : 09.EC.40

Group : 09

Subgroup : EC

Nickel-Strunz Number	Mineral Name	Formula
09.EC.40	montmorillonite	(Na,Ca)0.3(Al,Mg)2Si4O10(OH)2·n(H2O)
09.EC.40	nontronite	Na0.3Fe+32(Si,Al)4O10(OH)2·n(H2O)
09.EC.40	volkonskoite	Ca0.3(Cr+3,Mg,Fe+3)2(Si,Al)4O10(OH)2·4(H2O)
09.EC.40	yakhontovite	(Ca,K)0.5(Cu,Fe+3,Mg)2(Si4O10)(OH)2·3(H2O)

Specimens

Localities

Uses