Pargasite - NaCa₂(Mg₄Al)(Si₆Al₂)O₂₂(OH)₂

Habit: Light brown, brown or greenish brown to dark green and black. Stout prismatic crystals or granular. Vitreous luster; transparent to translucent. White streak.

Environment: Found in skarns metamorphosed from siliceous limestones, schists and amphibolites; also forms in andesitic volcanic and altered ultramafic rocks.

Etymology: From its occurrence in the Pargas Valley, Finland.