Stilbite

Stilbite is one of the highest sought after zeolite-based minerals for gem collectors because of the unique crystallization patterns it forms. You can find it in areas containing prehistoric volcanic rock, with India being the greatest source. Derivatives of Stilbite are used in water filtration systems. Stilbite is named for the Greek word 'stilbein', which means "to glitter", in reference to the luster of this mineral which is pearly on cleavage surfaces. 

Color: Colorless, white, pink.

Hardness: 3.5-4 on Mohs scale.