Numerous clay beds of montmorillonite along with fresh ash beds are commonly associated with the zeolite beds. The zeolite beds are usually light in color and low in density and reflect the volcanic ash genesis of the bed. (See Fig. 3.5) Analcime, mordenite, and laumontite have been reported in a wide variety of sedimennnttts in areas of Russia and Siberia (22). Mordenite and clinoptilolite have been found in Japan in glassy volcanic(23). Phillipsite, chabazite, and herschelite have been reported in Italy.