Minerals I.Minerals are all around us A.Minerals have four characteristics 1.Formed in nature a.Rocks usually contain two or more minerals b.All minerals can be formed without animals, but some are formed by animals (shells and bone) c.Halite (table salt) forms where ocean water evaporates d.Granite contains many minerals formed when molten rock cools 2.Solid a.Has a definite volume and rigid shape b.Liquids and gases are not minerals, liquid water is not a mineral but ice is a mineral

Minerals 3.Definite chemical makeup a.Each is formed from a unique combination of atoms from certain elements b.An element is a substance that has only one type of atom (gold and copper) c.Most minerals are compounds, having two or more types of atoms or elements (Halite has one sodium atom for every one chlorine atom) d.How the atoms are arranged is also important to the identity of the mineral (Graphite and diamonds) 4.Crystal structure a.Orderly, repeating 3-D pattern b.Sometimes same elements arranged in a different pattern (graphite and diamonds) c.Perfect crystals only form in open space which is not in abundance within earth’s crust

B.Minerals are grouped according to their composition 1.The 30 minerals that make up most of the crust are called rock-forming minerals a.Silicates- contain silicon and oxygen 1)Common ones- quartz, feldspar, and mica 2)90% of these are silicates- most of the crust is made of silicon and oxygen b.Carbonates- contain carbon and oxygen 1)Calcite- seashells 2.Oxides- metal combined with oxygen a.This group is what we refine most metals from b.Hematite is a source of iron Minerals