Scolecite

Scolecite is a member of the Zeolite Group and named from the Greek, 'skolex' meaning 'worm' in reference to the mineral's reaction to the blowpipe flame.  Scolecite occurs with other zeolites primarily as a cavity mineral in basalts.

Formula: CaAl2Si3O10 · 3H2O
Hardness: 5 - 5½