It is made both by the processing of the minerals trona (Na3H (CO3) 2. 2H2O) and nahcolite (NaHCO3), and by processing sodium carbonate-rich waters (called brines).    From Wordnik.com.  [Soda ash or Trona] Reference

2.2.5 Trona and nahcolite extraction in China 12 2.3.    From Wordnik.com.  [Glass Production in Emerging Economies to Drive Soda Ash Demand -- LONDON, September 13, 2010 /PRNewswire/ --] Reference

5.46.2 Production of soda ash from nahcolite in Colorado 174.    From Wordnik.com.  [Glass Production in Emerging Economies to Drive Soda Ash Demand -- LONDON, September 13, 2010 /PRNewswire/ --] Reference

(30); records from the goethite and nahcolite proxies are excluded because they are not yet widely applied.    From Wordnik.com.  [Watts Up With That?] Reference