Word Study
Trona
CIDE DICTIONARY
Trona, n. [Of Egyptian or North African origin.].
A native double salt, consisting of a combination of neutral and acid sodium carbonate, Na2CO3.2HNaCO3.2H2O , occurring as a white crystalline fibrous deposit from certain soda brine springs and lakes; -- called also urao , and by the ancients nitrum . [1913 Webster]
For further exploring for "Trona" in Webster Dictionary Online