Glauconite forms by three principal processes: alteration of the fecal pellets of bottom-dwelling organisms; modification of particles of illitic and biotitic clays by seawater; and direct precipitation from seawater. Particles of glauconite are generally sand-sized or finer.

Where is glauconite mined?

Glauconite forms under reducing conditions in sediments and such deposits are commonly found in nearshore sands, open oceans and the Mediterranean Sea. Glauconite remains absent in fresh-water lakes, but is noted in shelf sediments of the western Black Sea.

Is glauconite a clay?

Glauconite is an authigenic mineral in the clay/mica family, with potassium in interlayers and with iron in octahedral layers.