Halite , Nahcolite Locality: Searles Lake , San Bernardino County , California , USA ( Locality at mindat.org ) Okay, halite is salt, but for one thing, it is just as legitimate a mineral as any other, even if you CAN eat it (not this though - it contains bacteria so don t lick it!). This batch of gorgeous halite specimens was mined recently in California, and they are REALLY distinctive. Look at the amazingly fine structure of the crystals and beautiful bright pink color! But more than that, they have this wonderful contrast with a uniquely new matrix covered with minute nahcolite . Bottom line: it is just a plain stunningly pretty mineral specimen from a recent find; I bought ALL OF THEM THAT WERE AVAILABLE from the one contact who brought them to a show this year in California. NOTE that they are sensitive to humidity. 9.3 x 7.0 x 4.9cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Nahcolite
Natural sodium bicarbonate — baking-soda mineral forming monoclinic crystals in saline lakes and lava tunnels.
Intro adapted from Wikipedia (CC BY-SA).
Nahcolite is an IMA-recognized mineral species in the carbonate class, with the chemical formula NaH(CO₃).
It crystallizes in the monoclinic crystal system (space group P2_1/n).
Key properties: Mohs hardness 2.5; specific gravity 2.21–2.24; White streak; Vitreous, resinous on cleavages luster; refractive index 1.488; optically biaxial.
IMA symbol Nah, grandfathered status — known before the IMA’s founding, named in 1929.
A precipitate from hot springs; as efflorescences around saline lakes and in brines; formed at a late stage in differentiated alkalic massifs; as a solid in liquid inclusions in a variety of other mineral species.
It is found associated with Trona, thermonatrite, thénardite, halite, gaylussite, burkeite, northupite, borax.
The name comes from the composition, NaHCO-lite.