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Download MINERALS: BUILDING BLOCKS OF ROCKS
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MINERALS: BUILDING BLOCKS OF ROCKS Elements naturally combine with other elements to produce MINERALS n n Over 100 known elements 3700 known minerals (dozens discovered every year) Minerals combine to form crystals Sometimes we can see the crystal formation, sometimes we need a microscope. Geologists ( geo means Earth) study rocks and minerals. Properties geologists use to classify rocks Colour Streak Lustre Hardness Crystal Structure Cleavage Magnetism Reaction to Chemicals COLOUR ~ Minerals occur in many different colours STREAK n n The powdery mark minerals make when scratched on a hard surface More reliable than colour LUSTRE n Degree of shininess n n n Metallic Glossy Dull Hardness (strength of the bond) n Mohs hardness scale n n Scratch one mineral against another to see how hard it is Scale 1 (softest) – 10 (hardest) n Crystal Structure Crystal size explains the speed a mineral cooled n n Large crystal = slowly cooled Small crystal = rapidly cooled CLEAVAGE n How minerals break or fracture n n Rough, uneven, parallel, thin flat sheets, cubes, 90˚, etc. Maximum of 6 directions MAGNETISM n n Ability to attract to a magnet Will only attract if IRON is present REACTION TO CHEMICALS n Minerals with carbonate materials react with acidic solutions (vinegar) n Fizzing and bubbling (carbon dioxide gas) EARTH S CRUST Rocks Lustre Streak Reaction Crystals Geology Magnetism Minerals Cleavage Colour Hardness
