Nahcolite
Nahcolite is a soft, colourless or white carbonate mineral with the composition of sodium bicarbonate NaHCO3 also called thermokalite. It crystallizes in the monoclinic system.
Nahcolite was first described in 1928 for an occurrence in a lava tunnel at Mount Vesuvius, Italy. Its work believe mentioned to the elements which compose it: Na, H, C, and O. It occurs as a hot spring together with saline lake precipitate or efflorescence; in differentiated alkalic massifs; in fluid inclusions as a daughter mineral phase and in evaporite deposits.
It occurs in connective with burkeite, northupite and borax. It has been filed in a Roman conduit at Stufe de Nerone, Campi Flegrei, most Naples; in the U. S. from Searles Lake, San Bernardino County, California; in the Green River Formation, Colorado and Utah; in the Tincalayu deposit, Salar del Hombre Muerto,