Once exposed to air, it alters very rapidly to thermonatrite. Color is usually colorless. Luster is dull. Diaphaneity is transparent. Crystal Habits include crystalline masses to 4cm, rarely anhedral crystals.
Fracture is conchoidal.
Hardness is 1. Streak is white. Associated Minerals include ussingite, villiaumite and most of the species found in sodalite xenoliths.