Trona
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Trona 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. Turkey is also a... Wikipedia
Cleavage: perfect,, and, indistinct
Color: Colorless (in transmitted light) or white, grey-white, also grey to yellowish grey, light yellow
Crystal class: Prismatic (2/m); (same H-M symbol)
Crystal habit: Columnar, fibrous and massive
Crystal system: Monoclinic
Formula (repeating unit): Na2CO3·NaHCO3·2H2O
Fracture: Brittle – subconchoidal