GEOLOGY 115. LESSON 8: GEM ENHANCEMENT. Enhancement is defined as any processing (other than fashioning) which improves the appearance or durability of a gem....
Uses of Shale. Some shales have special properties that make them important resources. Black shales contain organic material that sometimes breaks down to form ......
Crystals and Gemstones. Crystals-- In science, a crystal. is a solid substance in which the atoms, molecules, or ions are arranged in an orderly repeating pattern ......
Iron normally does not occur as a free element in the earth. In fact, iron was not of much value to humans until they learned how to free iron from its ......
1.2 Sheet silicates (phyllosilicates) An important group of minerals, especially within the topmost 20 kilometers of the crust. All sheet silicates are hydrous....