Pectolite (Silicate-Single Chain Silicate) 

Hardness: 5.0
Specific Gravity: 2.9

Characteristics: Pyroxenoid; usually white, colorless or gray; two perfect prismatic cleavages; perfect fracture; vitreous luster; yellow flame; decomposes in HCl and forms silica gel.

Found in cavities in basalts; hydrothermal deposits; serpentinites; contact metamorphosed limestones.

(Primary text: Perkins, D. 2002. Mineralogy. Prentice Hall.)