The size of these channels controls the size of the molecules or ions and therefore a zeolite like stellerite can act as a chemical sieve. Stellerite's structure contains rings of alumino-silicate tetrahedrons oriented in one direction and this produces the prominant pinacoid faces, the perfect cleavage and the unique luster on those faces. Color is colorless or white and rarely tinted pink, yellow or brown. Luster is vitreous to pearly especially on the prominant pinacoid and cleavage surfaces. The prominant pinacoid is sometimes but rarely modified by other pinacoid and prism faces.
Cleavage is perfect in one direction parallel to the prominant pinacoid.
Fracture is uneven. Hardness is 3.5. Streak is white. Associated Minerals are quartz , calcite , apophyllite , babingtonite , heulandite , stilbite , natrolite and other zeolites . Best Field Indicators are crystal habit, luster, density and associations.