Scolecite can therefore be distinguished from natrolite by an optical examination, since the acicular crystals do not extinguish parallel to their length between crossed nicol prisms.

Cleavage is perfect in two directions parallel to the length of the crystals; the mineral is brittle with an irregular fracture.

Scolecite is pyroelectric and piezoelectric, sometimes fluorescent yellow to brown in longwave and shortwave ultraviolet light.

It is a mineral of secondary origin, and occurs with other zeolites in the amygdaloidal cavities (cavities filled with secondary minerals) of weathered basalts, also in gneisses and amphibolites, and in laccoliths and dikes derived from syenitic and gabbroic magmas, and in contact metamorphic zones.

It is a hydrothermal mineral derived from low temperature alteration of basalts and related rocks, associated with other zeolites, calcite, quartz and prehnite.

Divergent groups of prismatic crystals are found in the basalt of Berufjörður near Djúpivogur, Suður-Múlasýsla, Iceland and in the Deccan Traps near Pune in India; hence the synonym poonahlite for this species.

Other occurrences include Riverside County, California; Skye, Scotland and Santa Catarina, Brazil.

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

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

It is also found in the region as massive radiating material with powellite, and in cavities in basalt as colorless, flattened crystals in radiating sprays on blocky green apophyllite covered by tiny, thin, colorless apophyllite plates.

[6] Scolecite has been reported from many other localities, including Antarctica, Australia, Austria, Brazil, Bulgaria, Canada, Chile, Czechoslovakia, Ethiopia, Faroe Islands, France, Germany, Greenland, Hungary, Iceland, Italy, Japan, Mexico, Mozambique, Nicaragua, Peru, Poland, South Africa, Sweden, Switzerland, Taiwan, United Kingdom, United States and Yugoslavia.