Narrower Terms (15)

• ▶ Anthracite coal
• ▶ Bituminous coal
• Cannel coal
• ▶ Carbonization
• Char
• Coal reserves
• Coaling
• ▶ Coke
• Electric power-plants--Conversion to coal
• Furnaces--Conversion to coal
• ▶ Lignite
• ▶ Maceral
• ▶ Sapropelites
• Subbituminous coal
• Torbanite