Mineral
Escolecita
CaAl₂Si₃O₁₀·3H₂O · Tectosilicatos
Scolecite is a tectosilicate of the zeolite group, a hydrated calcium zeolite occurring in cavities in basalts and other volcanic rocks.
It forms by hydrothermal processes in basaltic cavities. Its acicular crystals occur as radial or spherulitic aggregates, and also as isolated needles. It is a typical mineral of India. Association with calcite is common in Deccan mineralisations.
It has an aluminosilicate framework with channels that host structural water and calcium. An aluminosilicate framework is a rigid mineral skeleton of silicon and aluminium that leaves internal voids. This crystal framework distinguishes it from carbonates such as calcite, which lack a framework and have more compact structures.
Etymology
From the Greek "skolex" (worm), referring to the appearance of the flexible needles when heated in a flame.