Eudialyte - Na₁₅Ca₆Fe₃Zr₃Si(Si₂₅O₇₃)(O,OH,H₂O)₃(Cl,OH)₂

Habit: Brown, yellow brown, yellow, pink, rose red or cherry red. Crystals short rhombohedral to long prismatic; more commonly irregular masses and vein fillings. Vitreous to dull luster; translucent. White streak.

Environment: Occurs in nepheline syenites, alkalic granites and associated pegmatites. May be a major constituent of both magmatic and late-stage pneumatolytic origin.

Etymology: From the Greek words for "easily" and "dissolved," alluding to its ready dissolution in acids.