Scolecite

Scolecite is a tectosilicate mineral belonging to the zeolite group; it is a hydrated calcium silicate. Only minor amounts of sodium and traces of potassium substitute for calcium. There is an absence of barium, strontium, iron and magnesium. Scolecite is isostructural (having the same structure) with the sodium-calcium zeolite mesolite and the sodium zeolite natrolite, but it does not form a continuous chemical series with either of them. 
Color: White, Transparent, Pink, Red