All of the following Hanksite crystals are from Trona, California.
A single crystal of Hanksite showing its quartz-like form (a prism terminated
by pyramids). The greenish, gray coloration is due to included clay.
This specimen is from Searls Lake, Trona, California.
This single crystal of Hanksite has
pinacoid terminations beveled by pyramid faces.
A group of Hanksite crystals.
This is what the Hanksite crystals
look like as they are collected from the mud at Trona, California.
These two pictures are of the same Hanksite crystal. The image on the left is under normal lighting (from above). The image on the left is backlit and shows aligned clay inclusions (hour glass shape) - presumably an exclusion process during crystal growth.
CHEMISTRY Na22KCl(CO3)2(SO4)9 Sodium-potassium chloro carbonate sulfate
CRYSTALLOGRAPHY Hexagonal
CRYSTAL GROWTH AND HABITS Hanksite typically grows as hexagonal prisms or tabular with pyramidal terminations. The prisms may also be modified by basal pinacoids.
COLOR AND OTHER OPTICAL PROPERTIES Hanksite is colorless but is usually tinted yellow or greenish gray but solid inclusions of clay. It is transparent to translucent.
HARDNESS 3 - 3.5
SPECIFIC GRAVITY 2.6 - 2.7
LUSTER Vitreous to dull
STREAK White
BREAKABILITY Hanksite has a good basal cleavage, an uneven fracture and is brittle.
OCCURRENCE Hanksite is an abundant mineral of the evaporite deposits of Searls Lake, California. Large crystals of Hanksite (and associated minerals) are retrieved from below the surface of the playa lake, from depths of 20 to 60 feet, by rapidly pumping the brine to the surface.
ASSOCIATED MINERALS Halite, Trona, Borax, Sulfohalite