Table 1.

Zeolite minerals occurring in deposits of the Olduvai Basin.

NameComposition*DEC**
*Composition: Passaglia and Sheppard (2001)
**DEC: dominant extra-framework cations, in order of abundance, for zeolites formed in saline alkaline environments, based on published data (Hay, 1964, 1966, 1980; Gude and Sheppard, 1978, 1988; Sheppard and Gude, 1968, 1969, 1973; Surdam and Eugster, 1976; Ratterman and Surdam, 1981).
AnalcimeNa2Al2Si4O12.16H2ONa
Chabazite(Ca0.5,K,Na)AlSi2O6.3H2ONa,Ca,K
Clinoptilolite(Na,K,Ca0.5)7Al7Si29O72.22H2ONa,Ca,K
ErioniteK2(Ca0.5,Na)7Al9Si27O72.28H2ONa,K,Ca
NatroliteNa2Al2Si3O10.2H2ONa
PhillipsiteK2(Na,Ca0.5)3Al5Si11O32.12H2ONa,K,Ca