Mineral description : Montmorillonite

Montmorillonite from Varuträsk.

Mineral class	Silicates : Phyllosilicates : Kaolinite - Montmorillonite group.
Chemical formula	(Na,Ca)0.33(Al,Mg)2Si4O10(OH)2.nH2O
Crystal system	Orthorombic.
Habitus	Earthy.
Cleavage
Hardness	1
Density	1.7-2.7
Color	White to gray, also as pinkish white, reddish white or brownish white.
Streak	White
Luster	Vitreous to resinous, translucent to transparent.
Description
Occurance	As a weathering product from silica poor rocks.
Associates
Notes
Locations	A rare mineral in Sweden. Varuträsk, Västerbotten. As pink aggregates and fracture fillings. created by weathering of petalite. Ultevis, Jokkmokk, Lappland. On weathered scapolite. Alnön, Sundsvall, Medelpad. Kinekulle, Västergötland. In weathered bentonite (volcanic ash). Boda, Dalarna. In weathered bentonite (volcanic ash).

To silicate index.

Mineral group index.

Main index.

If you have some questions, suggestions or comments you are welcome to write me a line or two.