Locality: Searles Lake, San Bernardino Co., California, USA Dimensions: 6.2 cm x 4.4 cm x 4.1 cm Nestled aesthetically in a vug of borax crystals is an octahedron of lustrous and translucent, lemon-yellow Sulphohalite, measuring 1.5 cm in length. It is surrounded by lustrous and translucent, colorless crystals of borax, to 1 cm across. This is a superb, sharp, and colorful example of this very rare species from its type locality. Ex. Al Ordway Collection. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Sulphohalite
Sulphohalite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Na₆(SO₄)₂ClF.
It crystallizes in the cubic crystal system (space group Fm-3m).
Key properties: Mohs hardness 3.5; specific gravity 2.49–2.5; Vitreous to greasy luster.
IMA symbol Slhl, grandfathered status — known before the IMA’s founding, named in 1888.
Found in evaporite deposits (Searles Lake, California, USA; Otjiwalundo salt pan, Namibia); a volcanic sublimate (Kamchatka Peninsula, Russia).
It is found associated with Hanksite, halite (Searles Lake, California, USA); trona, thénardite, pirssonite (Otjiwalundo salt pan, Namibia).
In allusion to sulfur and sodium chloride, (halite), in the composition, neglecting fluorine, the presence of which was unnoticed in the original analysis of type material.