Vesuvianite - Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH)₄

Habit: Green or chartreuse, but may be white, yellow, pink, yellow brown, greenish yellow, brown, red, black, purple or blue. Commonly short pyramidal to long prismatic crystals, but can be in many forms, even on one sample; columnar, granular and massive also common. Vitreous to resinous luster; transparent to translucent. White streak.

Environment: A rock-forming or accessory mineral in skarns, rodingites and altered alkali syenites; frequently associated with grossular, wollastonite, diopside and calcite.

Etymology: From the locality where it was discovered, Mount Vesuvius, in Italy.