Note: Chlorhexidine may cause staining of the tooth, tooth filling, and dentures or other mouth appliances. Tetracycline use during tooth development phases (from the last half of pregnancy through eight years of age) may cause permanent discoloration (yellow, gray, brown) of teeth.
What is Coal made of? Coal is made from trees or plants that decayed on the ground for millions of years. The remains of various plants and trees then mixed with the other components of the ground and eventually going through several natural processes making them more like solid rocks.
Â· just now. 1  Coal is formed from plant remains that have been compacted, hardened, chemically altered, and metamorphosed by heat and pressure over geologic time. It is suspected that coal was formed from prehistoric plants that grew in swamp ecosystems.