Black carbon (4)
I believe the answer is:
coal
(Other definitions for coal that I've seen before include "Char" , "slack" , "This consists mainly of carbon" , "Carbon fuel" , "Carbonized vegetable matter" .)
I believe the answer is:
coal
(Other definitions for coal that I've seen before include "Char" , "slack" , "This consists mainly of carbon" , "Carbon fuel" , "Carbonized vegetable matter" .)