HOW MANY DIFFERENT MINERALS EXIST ON EARTH?
There are over 2000 known varieties of minerals. However, most of these are fairly rare, and are sought by mineral collectors for their gem quality. The more common minerals add up to about 200 or so varieties. The most important of the common minerals are silicates (compounds containing the elements silicon and oxygen, and usually a metallic element) and carbonates (carbonates containing carbon, oxygen, and a metallic element). The other common minerals may be collectively called non-silicates.
