Montmorillonite [ (Na,Ca)0.3(Al,Mg)2Si4O10(OH)2·nH2O ]

Image of Montmorillonite

Material properties

Formulas (Na,Ca)0.3(Al,Mg)2Si4O10(OH)2·nH2O, (Na,Ca)0.3(Al,Mg,Fe)2Si4O10(OH)2·nH2O
Abbreviation Mnt
IMA Status Grandfathered (pre-IMA), 1847
Crystal symmetry Monoclinic, Point group 2/m, Space group C2/m (#12)
Classifications Minerals containing H2O, Minerals containing OH, Smectite (group)
Variant Fe
Reflectance lines OH, Si-O
Search other databases webmineral.com, mindat.org, rruf.info, mineralienatlas.de, Handbook of Mineralogy, American Mineralogist Crystal Structure Database
Tags Aluminosilicate, Hydrated, Hydroxide, Mineral

Composition

Al, O, Mg, Si, H, Na, Ca

Specimens of Montmorillonite

Name Owner Materials Phase purity Image Spectra Techniques
SAz-1 Montmorillonite CSIRO Montmorillonite (99.2%) 99.2 0 —
SCa-3 Montmorillonite CSIRO Montmorillonite (97.7%), Quartz 97.7 0 —
Swy-1 Montmorillonite CSIRO Montmorillonite (90.1%), Orthoclase, Quartz 90.1 0 —
MT6899 Montmorillonite CSIRO Calcite, Montmorillonite (85.5%) 85.5 0 —
Swy-2 Montmorillonite CSIRO Montmorillonite (84.9%), Orthoclase, Quartz 84.9 0 —
STx-1 Montmorillonite CSIRO Cristobalite, Montmorillonite (80.3%) 80.3 0 —
Swa-1 Ferruginous smectite CSIRO Goethite, Montmorillonite (var. Fe) (79.0%), Quartz, Smectite (var. Fe) 79.0 0 —
SBCa-1 Beidellite CSIRO Anatase, Beidellite, Kaolinite, Montmorillonite (70.8%), Quartz 70.8 0 —
M2803 Chrysocolla and Malachite CSIRO Chrysocolla, Goethite, Hematite, Malachite, Montmorillonite (21.4%), Quartz 21.4 0 —
API H46-1 Palygorskite CSIRO Montmorillonite (20.2%), Palygorskite, Quartz, Sepiolite 20.2 0 —
MT8388a Palygorskite CSIRO Goethite, Montmorillonite (16.4%), Palygorskite, Quartz 16.4 0 —
PF1-1 Palygorskite CSIRO Fluor-elbaite, Goethite, Montmorillonite (14.4%), Palygorskite, Quartz 14.4 0 —
MES078 Hedenbergite / Montmorillonite CSIRO Hedenbergite, Magnesite, Montmorillonite (14.0%), Pyrite, Quartz 14.0 0 —
M0891 Chrysocolla CSIRO Chrysocolla, Goethite, Hematite, Microcline, Montmorillonite (12.3%), Quartz 12.3 0 —
M1646 Chrysocolla CSIRO Chrysocolla, Goethite, Hematite, Malachite, Montmorillonite (5.5%), Quartz 5.5 0 —
M0834 Ankerite CSIRO Albite (var. Ca), Ankerite, Augite, Forsterite (var. Fe), Ilmenite, Montmorillonite (5.2%), Sanidine 5.2 0 —
MT8407 Meionite CSIRO Kaolinite, Meionite, Montmorillonite (3.2%), Muscovite, Muscovite-1M, Muscovite-2M1, Prehnite, Pumpellyite-(Mg) (var. Cr), Scapolite (group) 3.2 1 Reflectance
APIH13 Halloysite CSIRO Albite, Halloysite, Halloysite (var. hkl), Illite-Smectite 12.0A, Kaolinite, Montmorillonite (2.8%), Orthoclase, Quartz 2.8 0 —