Chemical Formula

Na15Ca6(Fe2+,Mn2+)3Zr3(Si25O73)(O,OH,H2O)3(Cl,OH)2

Hardness (Mohs)

5-5.5

Crystal System

Trigonal

Streak

White

Luster

Vitreous to greasy

Diaphaneity

Translucent to opaque

Color

Red, pink, brownish-red, reddish-brown, rarely yellow or green

Crystal Habit / Mode of Occurrence

Tabular to short prismatic crystals, often with hexagonal outline; granular, massive