All are tectosilicates (framework silicates), zeolite group
Specific gravity: 2.1 to 2.2
Hardness: 3½ to 4
Colour: White, Reddish white, red
Volcanic igneous environments
Clinoptilolite is most commonly formed as a devitrification product of silicic volcanic glass from tuff (consolidated pyroclastic rock). It also occurs in cavities in rhyolites, andesites, and basalts.