Minerals Mar 3 2009
Minerals • are all non-living solid material • most minerals are rare. Like gold • common minerals are found throughout the earth’s crust. Like talc • a mineral can be an element (a pure substance) or a compound (two or more substances)
Identifying Minerals • 1) The Mohs hardness scale • - German scientist, Friedrich Mohs developed a scale of mineral “hardness” • - a useful tool for mineral identification because there are over 3000 minerals
2) Lustre • some minerals, such as gold, appear shiny. • some minerals, like talc, can appear dull. • the lustre of an object depends on how light is reflected from it’s surface.
3) Colour • colour is the most attractive properties of minerals
4) Cleavage and Fracture • if a mineral breaks in smooth flat surfaces it has cleavage • minerals which break with rough or jagged edges it has fracture