Na-montmorillonite (inf. 0.1 mm) | ROMA

Matter

Family: mineral
Comments: Impurities: quartz, feldspar, mica and/or illite, calcite, hematite, kaolinite(?) and/or chlorite(?) (Chipera & Bish 2001). Impurities (13.3% wt.%) in the fraction <2µm of SWy-2: 5.2% Quartz, 0.1% Plagioclase, 0.4% Calcite, 0.2% Dolomite, 1.3% Kaolinite, 0.2% Chlorite, 4.4% Clinopyroxene, 1.4% Orthopyroxene (Vogt et al. 2002). INFRARED SPECTROSCOPY: Typical spectrum for Wyoming bentonite with a moderate Fe+3 content (band at 885 cm-1). Quartz is detectable (band at 780, 800,698, 400, and 373 cm-1), a trace of carbonate (band at 1425 cm-1).

Database

Experimentalists

Matter origin

Level: local matter
Origins: natural terrestrial
Provider: Source Clays Repository - The Clay Minerals Society, Purdue University, West Lafayette, IN, USA
Local reference code: SWy-3

Body name: Earth
Terrain type: mineral surface
Place: Newcastle formation (cretaceous), Crook County , Wyoming , United States

Comments: According to the Clay Minerals Society, SWy-3 is the same as SWy-1 and SWy-2. SWy-2 and SWy-3 were collected from the same mine from where SWy-1 was collected at two later occasions).

Preparation: sieved fraction
Phase type: solid
Component type (group): mineral (silicate mineral), mineral (non-silicate mineral)

Grain sizes

Grains	Size min	Size max	Size median	Size width	Size mass fraction	Grain shape
#1		0.1 $mm$			1.0	None

Oxides

Formula	$SiO_{2}$	$Na_{2}O$	$CaO$	$K_{2}O$	$Al_{2}O_{3}$	$Fe_{2}O_{3}$	$FeO$	$MnO$	$MgO$	$TiO_{2}$	$P_{2}O_{5}$	$CO_{2}$	$F$	$S$
Mass fraction (%)	62.9	1.53	1.68	0.53	19.6	3.35	0.32	0.006	3.05	0.09	0.049	1.33	0.111	0.05

Oxides comments

Loss on heating: -550°C: 1.59%, 550-1000°C: 4.47%.

Number

Mode of mixing

homogeneous mixing

Materials

Name	Arrangement	Mass fraction	Abundance comments
Na-Montmorillonite with adsorbed and interlayer water	homogeneously mixed (with interlayer and adsorbed water)	0.75 $\pm$ 0.05
Quartz	homogeneously mixed	0.08 $\pm$ 0.04	unknown mass fraction: 8% as for SWy-2 ?
Plagioclase	homogeneously mixed	0.16 $\pm$ 0.08	unknown mass fraction: 16% as for SWy-2 ?
Gypsum	homogeneously mixed	0.005 $\pm$ 0.003	unknown mass fraction: 1% gypsum + mica and/or illite + kaolinite(?) and/or chlorite(?) for SWy-2 (Chipera & Bish 2001)
Calcite	homogeneously mixed	0.007 $\pm$ 0.005	unknown mass fraction: 0.4%-1% as for SWy-2 ?
Dolomite	homogeneously mixed	0.002 $\pm$ 0.002	unknown mass fraction: 0.2% as for SWy-2 ?)
Kaolinite	homogeneously mixed	0.013 $\pm$ 0.01	unknown mass fraction: 1.3% as for SWy-2 ?
Chlorites	homogeneously mixed	0.002 $\pm$ 0.002	unknown mass fraction: 0.2% as for SWy-2 ?
Clinopyroxenes	homogeneously mixed	0.044 $\pm$ 0.04	Mostly Augite - unknown mass fraction: 4.4% as for SWy-2 ?
Orthopyroxenes	homogeneously mixed	0.014 $\pm$ 0.01	unknown mass fraction: 1.4% as for SWy-2 ?

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