The Earth's surface is made up mainly of solid silicates. According to size, they are classified into geologic bodis, rocks, and minerals. Geologic bodies constitute directly Earth's crust and their general size is from 1m to 10km, being studied normally by fieldworks. Rocks are constituent materials of geologic bodies and their typical size is hand specimen, being observed in laboratories. Rocks are heterogeneous, being composed of many phases. Each phase is called mineral, and has homogeneous chemical and physical behaviors. The size of minerals varies from micrometric to centimetric scale, therefore they are studied in laboratories, especially with help of microscope. The research field specifically in minerals is called mineralogy.