Rocks and Minerals Earth and Life Science PDF

ROCKS AND MINERALS E A RT H A N D L I F E S C I E N C E MS. GRACE MONICA LEBRILLA GUIDE QUESTIONS: 1.What are minerals? 2.What are rocks? 3.What are rocks made up of? 4.How are rocks and gems different from each other? What lesson can we learn from gems?  MINERALS VS. ROCKS Min...

ROCKS AND MINERALS E A RT H A N D L I F E S C I E N C E MS. GRACE MONICA LEBRILLA GUIDE QUESTIONS: 1.What are minerals? 2.What are rocks? 3.What are rocks made up of? 4.How are rocks and gems different from each other? What lesson can we learn from gems?  MINERALS VS. ROCKS Minerals – a solid formation that naturally occur in the Earth. Rocks – solid combination of mineral formations.  MINERALS Minerals are naturally occurring, inorganic solid substances with a specific chemical composition and a crystalline structure. They are the basic building blocks of rocks and are found in the Earth's crust. HOW ARE ROCKS FORMED? Rocks are formed by the aggregation of rock- forming minerals. PROPERTIES OF MINERALS Luster – the quality and intensity of reflected light exhibited by the mineral Hardness – it is a measure of the resistance of a mineral (not specifically surface) to abrasion Color and streak – maybe a unique identifying property of certain minerals (e.g. malachite – green, azurite – blue) ▪ Streak – the color of a mineral in powdered form Crystal Form/Habit – the external shape of a crystal or groups of crystals is displayed /observed as these crystals grow in open spaces.  PROPERTIES OF MINERALS Cleavage – it is the property of some minerals to break along parallel repetitive planes of weakness to form smooth, flat surfaces. Fracture – some minerals may not have cleavages but exhibit broken surfaces that are irregular and non-planar. Others – there are certain unique properties of minerals that actually help in their identification (e.g. magnetism, odor, taste, tenacity, reaction to acid, etc.). – Magnetite is strongly magnetic; sulfur has distinctive smell; halite is salty; calcite fizzes with acid as with dolomite but in powdered form CLEAVAGE FRACTURE C L A S S I F I C AT I O N OF MINERALS  MINERALS Minerals are naturally occurring, inorganic solid substances with a specific chemical composition and a crystalline structure. They are the basic building blocks of rocks and are found in the Earth's crust. 1. SILICATES Minerals containing two of the most abundant elements in the earth’s crust, namely, silicon and oxygen. Ex. quartz, beryl (emerald), and feldspar. 2. OXIDES Minerals containing oxygen anion (O2-) combined with one or more metal ions. Ex. Hematite, spinel, sapphire 3. SULFATES Minerals containing sulfur and oxygen anion (SO4)2- combined with other ions. Ex. Baryte, gypsum, and anhydrite. 4. SULFIDES Minerals containing sulfur anion S2- combined with one or more ions. Ex. pyrite, galena, and sphalerite. 5. CARBONATES Minerals containing the carbonate anion (CO3)2- combined with other elements. Ex. Calcite, magnesite, and dolomite. 6. NATIVE ELEMENTS Minerals that form as individual elements. a. Metals and Inter-metals – minerals with high thermal and electrical conductivity, typically with metallic luster, low hardness (gold, silver). b. Semi-metals – minerals that are more fragile than metals and have lower conductivity (arsenic, bismuth). c. Nonmetals – nonconductive (sulfur) 7. HALIDES Minerals containing halogen elements combined with one or more elements. Ex. fluoride, halite, and chloride. C L A S S I F I C AT I O N O F R O C KS CLASSIFICATION OF ROCKS Igneous rocks Sedimentary rocks Metamorphic rocks IGNEOUS ROCKS Formed by volcanic activity Solidification of molten rock material Intrusive igneous rocks – crystallize within the earth’s surface – Granite, gabbro, peridotite, diorite Extrusive igneous rocks – solidify onto the surface after eruption – Basalt, obsidian, pumice, rhyollite  INTRUSIVE IGNEOUS ROCKS Diorite Gabbro Granite  EXTRUSIVE IGNEOUS ROCKS Basalt Obsidian Pumice SEDIMENTARY ROCKS Formed by sedimentation; deposition of materials at the earth’s surface Clastic sedimentary rocks – formed from mechanical weathering debris – Conglomerate, breccia, sandstone, siltstone, and shale Chemical sedimentary rocks – formed when dissolved materials precipitate from solution – Limestones, chert, flint, iron ore Organic sedimentary rocks – formed from the accumulation of plant or animal debris – Coal, some dolomites CLASTIC SEDIMENTARY ROCKS Breccia Conglomerate Sandstone  CHEMICAL SEDIMENTARY ROCKS Flint Iron ore Chert  ORGANIC SEDIMENTARY ROCKS Coal Dolomite METAMORPHIC ROCKS Rocks modified by heat, pressure, and chemical processes while buried deep below the Earth’s surface. Foliated metamorphic rocks – have a layered or banded appearance produced by exposure to heat and directed pressure. – Gneiss, schist, slate Non-foliated metamorphic rocks – do not have layered or banded appearance – Quartzite, marble, hornfels, novaculite FOLIATED METAMORPHIC ROCKS Gneiss Schist Slate  NON-FOLIATED METAMORPHIC ROCKS Novaculite Marble Quartzite THE ROCK CYCLE