What's a rock?
Rocks are aggregates of minerals usually several, but sometimes only one or two. Similarly, minerals are either free, uncombined native elements, or elemental compounds. gold, silver, and copper are metallic elements.
Feldspars, pyroxenes, amphiboles, and micas are rock-forming silicates - compounds in which metallic elements combine with linked si-o tetrahedra.
What's a mineral?
With a few notable exceptions (water, mercury, opal), minerals are solid, inorganic elements or elemental compounds. They have definite atomiv structures and chemical compositions which vary within fixed limits. Each and every quartz crystal, whether crystallized in a sandstone vein, or in volcanic lava, possesses the same chemical and physical properties.
How rocks are formed?
Geological processes work in constant cycles - redistributing the chemicals elements, minerals, and rocks within and at the surface of the earth. The processes that occur within the earth, such as metamorphism (changing) and mountain buildind, are driven by the earth's internal heat. Surface processes, such as weathering, are activated by the sun's energy.