Occurs in Pinal County.
Chemical Formula: (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2·nH2O
Specific Gravity: 1.7-2
Hardness: 1-2
Montmorillonite is a clay mineral that often forms as soft, flexible sheets or masses. It is a major component of bentonite and is used in various applications.