(trisodium hydrogendicarbonate dihydrate, also sodium sesquicarbonate dihydrate, Na2CO3•NaHCO3•2H2O) is a non-marine evaporite mineral. It is mined as the primary source of sodium carbonate in the United States, where it has replaced the Solvay process used in most of the rest of the world for sodium carbonate production ( from Wikipedia).
Is a common mineral ,but difficult to cut and polish due to it's low fardness : is 2.5.It may be soluble in water,therefore must be handle with care.It is fluorescent in yellowish at uv short wave.
It comes from Searles Lake ,California.
Size: 12.5x8.5x7.1 mm