Hanksite crystal from Searles Lake , California . Pen in background for scale. — Photo: Matt Affolter(QFL247) ( talk ) (Transferred by Citypeek /Original uploaded by Matt Affolter(QFL247) ) · CC BY-SA 3.0
Hanksite
One of the very few minerals carrying both sulfate and carbonate ions — a sodium-potassium sulfate-carbonate-chloride from Searles Lake.
Intro adapted from Wikipedia (CC BY-SA).
Hanksite is an IMA-recognized mineral species in the sulfate class, with the chemical formula KNa₂₂(SO₄)₉(CO₃)₂Cl.
It crystallizes in the hexagonal crystal system (space group P6_3/m).
Key properties: Mohs hardness 3–3.5; specific gravity 2.562; White streak; Vitreous to dull luster; refractive index 1.471; optically uniaxial.
IMA symbol Hks, grandfathered status — known before the IMA’s founding, named in 1885.
Found in lacustrine evaporite deposits.
It is found associated with Halite, borax, trona, aphthitalite (Searles Lake, California, USA).
The mineral was named to honor Henry Garber Hanks (1826–1907), for his service as first State Mineralogist of California, USA.