Chemical Formula: Na22K(SO4)9(CO3)2Cl
Locality: Searles Lake, San Bernardino Co. California.
Name Origin: Named for H. G. Hanks, American geologist.
Hanksite is a sulfate mineral, distinguished as one of only a handful that contain both carbonate and sulfate ion groups. It has the chemical formula: Na22K(SO4)9(CO3)2Cl.
Occurrence
It was first described in 1888 for an occurrence in Searles Lake, California and named for American geologist Henry Garber Hanks (1826–1907). Hanksite is normally found in crystal form as evaporite deposits. Hanksite crystals are large but not complex in structure. It is often found in Searles Lake, Soda Lake, Mono Lake, and in Death Valley. It is associated with halite, borax, trona and aphthitalite in the Searles Lake area.
Physical Properties
Cleavage: {0001} Good
Color: Colorless, Gray, Grayish black, Yellow, Yellowish white.
Density: 2.5
Diaphaneity: Transparent
Fracture: Conchoidal – Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Hardness: 3 – Calcite
Luminescence: Fluorescent, Long UV=weak yellow.
Luster: Vitreous – Greasy
Magnetism: Nonmagnetic
Streak: white