scolecite

From the Greek mesos, "middle", as its composition lies between natrolite and scolecite.

The structure of the aluminosilicate framework is the same for scolecite, natrolite and mesolite.

Scolecite was first described from Kaiserstuhl in Baden-Württemberg in 1813.

Associated minerals include prehnite, scolecite and mesolite.

It has nearly the same angles between the crystal faces as does natrolite, but natrolite is orthorhombic and scolecite is monoclinic.

(Natrolite, NaAlSiO.2HO, does not directly form epitaxial overgrowths on scolecite).

The scolecite is commonly found alone or on stilbite and is covered with laumontite or colourless, pale green or white fluorapophyllite.

Most of the world's finest scolecite specimens are found in the Tertiary Deccan Basalt near Nasik, Pune, in the state of Maharashtra, India.

When weathered they are filled with calcite, chlorite, serpentine and, especially where the lavas contain nepheline or leucite, are often rich in zeolites, such as analcite, prehnite, natrolite, scolecite, chabazite, heulandite, etc.