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.
by Brian Thomas, M.S. *. Coal, oil, and natural gas are precious earth materials that are used to power many modern human activities. It is commonly believed that these fossil fuels formed over millions of years after plant and animal remains were buried and then subjected to tremendous pressures.