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MINERALS AND ROCKS. 1st grade. The Earth’s crust is made up of ROCKS. The rock is made up of minerals . MINERAL:. A MINERAL IS A SOLID SUBSTANCE WHICH ORIGINATES THROUGH ONE OF THE EARTH’S NATURAL PROCESSES. The general definition encompasses the following criteria :
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MINERALS AND ROCKS 1st grade
TheEarth’scrustismade up of ROCKS.The rock ismade up of minerals.
MINERAL: • A MINERAL IS A SOLID SUBSTANCE WHICH ORIGINATES THROUGH ONE OF THE EARTH’S NATURAL PROCESSES. • The general definitionencompassesthefollowingcriteria: • Natural occurring • Stable at roomtemperature • Representedby a chemical formula • Usuallyabiogenic • Orderedatomicarrengement
MOST COMMON ELEMENTS IN MINERALS: • Oxygen • Silicon • Aluminium • Iron • Calcium • Sodium • Potassium • Magnesium
CRYSTAL • Whentheexternalshape of the mineral reflectsitsinternalstructure, wecallit a crystal. • (Crystal of AmethystQuartz) (Cuarzo amatista)
PHYSICAL PROPERTIES OF MINERALS • COLOUR: someminerals are alwaysthesamecolour (cinnabar), othersshawvariety of colour. (Quartz) • LUSTER (brillo):itishowminerals look whenitreflects light: metallic,vitreous, pearly,dullorgreasy.
PROPIERTIES • HARDNESS (dureza): itmeasuresthecomparativeeaseordifficultywithwhich a mineral maybescratched. • Fingernail: lowhardness • Nail: medium • Itscatchesglass: high • Mohs scale
PHYSICAL PROPERTIES • STREAK (RAYA): itisthecolour of the mineral whenitismadeintopowder. • FRACTURE AND CLEAVAGE (Fractura): itisthetendency of a mineral to break along irregular surfaces (fracture) oralong flat planarsurfaces (cleavage).
ROCKSAggregates of mineralswhichhavebeenformed in a natural process.Accordingtothatprocessrocks can besedimentary, metamorphicorigneus.
SEDIMENTARY ROCKS • These are formedfrommaterialscalledsediments, which are slowlydeposited in someareas (oceans and lakes). • Sedimentsaccumulateforming horizontal layeerscalledstrata. • Examples: limestone: piedra caliza • sandstone: arenisca
METAMORPHIC ROCKS • These are formedfromotherrocksthat are transformedbythehighpressure and temperature in deepzones of theEarth’scrust. Theprocessiscalledmetamorphism. • Claychangesintoslate. (arcilla se transforma en pizarra) • Limestonechangesintomarble .(caliza se transforma en mármol)
MAGMATIC OR IGNEOUS ROCKS • In deepzones of theEarth’scrustthere are extremlyhightemperatureswhich can meltrocks, whichbecomemoltenmaterialscalledmagama. Whenthis magma coolsdown and solidifies, itformsigneusrocks. • Plutonicrocks: magma coolsdownveryslowlyundertheEarth. Granite (granito) • Volcanicrocks: magna coolsdownquickly as it comes out of thevolcano. Basalt and pumice (basalto y pumita)