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NTclarain
 durain
 fusain
 vitrain
RTbituminous coal
 coal
 humic coal
 macerals
 sapropelite
SNVisible bands in humic coals. Lithotypes for bituminous coal are vitrain, clarain, durain, and fusain; beds or bands of cannel and boghead coals (sapropelite) are sometimes included. Added to Thesaurus in 1998.