CHEMISTRY - Na2(SO4)
CRYSTALLOGRAPHY - Orthorhombic Dipyramidal
CRYSTAL GROWTH AND HABITS - Crystals are typically tabular and occasionally prismatic. It also forms powdery crusts.
COLOR AND OPTICAL PROPERTIES - Colorless to grayish white or yellow. Transparent to translucent.
HARDNESS - 2.5 - 3
SPECIFIC GRAVITY - 2.66 - 2.67
LUSTER - Vitreous to slightly resinous
STREAK - White
BREAKABILITY - Perfect cleavage along {011}, fair along {101}. Fracture is uneven to hackly.
OCCURRENCE - Thenardite is a mineral that forms from the evaporation of bodies of water. It is especially found in playa lakes.
ASSOCIATED MINERALS - Mirabilite, Glauberite, Gypsum, Halite, Borax (Tincalconite).
MINERAL NAME - Named for the French Chemist Louis Thenard.