Smectite
Videos
A smectite is a mineral mixture of various swelling sheet silicates, which have a three-layer 2:1 structure and belong to the clay minerals. Smectites mainly consist of montmorillonite, but can often
Scanning electron microscope (SEM) photograph of smectite clay – magnification 23,500 – U.S. Geological Survey – Tuckup Canyon
Typical cracks pattern of a smectite-rich bentonite after its desiccation and shrinkage
Typical volcanic eruption plume whose ashes' weathering after contact with seawater is the main source of smectite. Leaching of most of amorphous silica leads to partial dissolution of obsidian, the main constituent of volcanic glass.
Bentonite
Videos
Bentonite is an absorbent swelling clay consisting mostly of montmorillonite which can either be Na-montmorillonite or Ca-montmorillonite. Na-montmorillonite has a considerably greater swelling capaci
Bentonite layers from an ancient deposit of weathered volcanic ash tuff in Wyoming
Gray shale and bentonites (Benton Shale; Colorado Springs, Colorado)
Making a bentonite slurry for fining after wine pressing