Color is usually white or colorless, but can be pale pink, gray, yellow, blue or violet. Luster is vitreous to silky or pearly. Crystals are transparent to translucent. Crystal Habits include tabular crystals and aggregate spherulites. Twinning forms stellate figures with wedge shaped spokes.
Fracture is uneven.
Hardness is 6 - 7. Streak is white. Associated Minerals include nepheline , aegirine , catapleiite , natrolite , fluorite , rhodochrosite , feldspars , micas and analcime . Best Field Indicators are crystal habit, cleavage, associations, locality and hardness.