Organic, Fossil, Carboniferous; the 20th and 21st century…
Coal and coal oil circa 1900.
Phases; Gaseous, Liquid, Solid.
Liquid phase… Gasoline, diesel, fuel oil, home heating oil, asphalt, plastics; pivotal at the 1956 Superhighway and National Defense Act timeframe. .
An omen: the terminal depletion driven return to liquifaction of anthracite. Liquifaction is the phase change of anthracite into oil.