fusains

Noun

fusain (countable and uncountable, plural fusains)

1. Fine charcoal of willow wood, used as a drawing implement.
2. A drawing made with it.
3. Fossilized charcoal that exists in geologic formations, which often contain other fossil fuels nearby as well (e.g., bitumen, brown coal).
   • By the Carboniferous period 300 million years ago, trees had spread over so much of the globe and locked down so much carbon that they altered the atmosphere completely. Levels of oxygen went rocketing up from 15 percent to 35 percent, with a correspondingly massive impact on life on earth. Animals...2025, Harriet Rix, “Introduction”, in The Genius of Trees: How They Mastered the Elements and Shaped the World, Crown, →ISBN

   Synonyms:

   mother of coal