Crude oil is oil that has been very bad, showing no sense of manners or social skills. It is often found in places that are unfit for proper society, dominated by corrupt businesses, dominated by corrupt governments, or all of the above.
Originally known as rock oil (or sometimes lewd oil) because it literally seeped out of rocks (like that creepy pervert at the mall), it is often colored black, brown, or even green (eww!), presumably due to improper hygiene.
Crude Oil has been implicated in a great many atrocities, crimes, wars, and other examples of bad behavior. It is very important to never trust the stuff! It is DANGEROUS! Furthermore, it is responsible for ruining countless holidays and beaches, killing countless marine animals, and worse.
Sour Crude Oil reeks of sulfur (eww!).
Finding and Finishing
Crude Oil usually dwells deep in the ground and is often brought up by steam. This is generally inadequate, however, and it is often sent to refining school before it is considered presentable enough to present to consumers.