Nitratine - NaNO₃

Habit: Colorless to white, tinged reddish brown or lemon yellow; gray with impurities. Rare as rhombohedral crystals; stalactitic, cotton-like, typically granular or in massive incrustations. Vitreous luster; transparent. White streak.

Environment: Principally occurs in bedded deposits formed in playas or in caves, deposited by seeping groundwater leaching nitrates from overlying rocks, especially in very dry and cold climates.

Etymology: From the nitrogen in its composition.