Unit 5: Minerals

Minerals Minerals are: Solid Formed in nature Inorganic Of a definite composition Composed of a particular crystal structure

Naturally Occurring and Inorganic Minerals are formed by natural processes Minerals are Inorganic Inorganic – not formed from living matter Minerals are not living and never were living Salt is a mineral, coal and sugar are not

Solids with Specific Composition All minerals are solid – definite shape, definite volume Most are compounds, some are elements Contain same elements in same ratio Ex: SiO2

Definite Crystalline Structure Crystals are solids with repeating patterns More space = better crystal formation

Definite Crystalline Structure

Formation of Minerals Minerals can form from Magma Magma – molten material found beneath Earth’s surface If magma cools slowly in Earth’s heated interior, large crystals can form If magma cools at Earth’s surface, or comes into contact with air or water, smaller crystals form

Minerals from Solution Minerals can also form from a solution Supersaturated solutions will cause crystals to precipitate If the liquid of a solution evaporates, the remaining elements form crystals

Mineral Groups Silicates – Silicon + Oxygen + Metal(s) Ex: Olivine - Mg2SiO4

Mineral Groups Carbonates – CO3 and Metal(s) Ex: Calcite - CaCO3

Mineral Groups Oxides – Oxygen and Metal(s) Ex: Hematite– Fe2O3 Sulfates – SO4 and Metal(s) Anhydrite CaSO4 Sulfides – Sulfur and Metal(s) Pyrite – FeS2 Halides – Halogen (Cl or F) and Metal(s) Halite - NaCl