The structure of the aluminosilicate framework is the same for scolecite, natrolite and mesolite. From the Greek "mesos", "middle", as its composition lies between natrolite and scolecite. Scolecite crystals appear to be monoclinic by X-ray analysis. Scolecite, like natrolite and mesolite, usually occurs as acicular (needle-like) and fibrous aggregations. Scolecite is usually colorless or white, but can also be pink, salmon, red or green.