A crystaline structure which has radioactive properties. Also can be used as a form of currency if mined and handled properly. Can be used as a weapon if mined and liquified. Has startling regrowth properties which make it particularly hard to control. The Scrin have a building which can increase regrowth rate of Tiberium. There are two known colors, green and a light blue color. Tiberium can be primarily found in the Command & Conquer Tiberium series.
Stay away from that tiberium if you value your life.