© Fall 2005, Pflugerville ISD, 8th Grade 8th Grade Science

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 Chapter 15- Rocks: Mineral Mixtures Section 1: From Minerals to Rocks Section 2: Igneous Rocks Section 3: Sedimentary Rock Section 4: Metamorphic Rock

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 What is a Mineral? What are some items you use in your everyday life that come from minerals? What Do You Think?

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 What is a Mineral? Halite Crystal (NaCl) All minerals must meet the following five characteristics:

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 What is a Mineral? Halite Crystal (NaCl) Natural, inorganic solid that forms a crystal lattice and has a chemical formula

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 What is a Mineral? Halite Crystal (NaCl) Since they form crystals, all minerals are ionic compounds

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Types of Minerals Minerals are grouped by the chemicals in them Silicate minerals contain silicon and oxygen Muscovite crystal under microscope

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Silicate Minerals Muscovite crystal under microscope Over 90% of the minerals in Earth’s crust are silicates

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Nonsilicate Minerals Calcite (CaCO3) Nonsilicates are minerals that do not contain silicon

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Nonsilicate Minerals Calcite (CaCO3) Nonsilicates are made of elements such as carbon, oxygen, iron and sulfur

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Nonsilicate Minerals Calcite (CaCO 3 ) Carbonates, such as calcite, are used in cement, building stone, and fireworks

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Nonsilicate Minerals Halite (NaCl) Halide minerals are used in fertilizer, or to season your food

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Nonsilicate Minerals Corundum (Al 2 O 3 ) Oxide minerals are used to make abrasives and aircraft parts

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Nonsilicate Minerals Gypsum (CaSO 4 2H 2 O) Sulfates are used in cosmetics, toothpaste, and paint

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Geologists use physical properties such as color, luster, streak, and many others to identify minerals

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Quartz/Amethyst Scepter (SiO 2 ) Quartz and amethyst are both SiO 2, but amethyst contains impurities that give it a purple color

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Quartz/Amethyst Scepter (SiO 2 ) Because a single mineral can be many colors, color is not a reliable way to identify a mineral

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Galena (PbS)- Metallic Luster The way the surface of a mineral reflects light is called luster

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Bauxite (Al 2 O 3 2H 2 O)- Earthy Luster Bauxite, the ore of aluminum, has a nonmetallic luster

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Streak is the color of a mineral in powdered form

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Hematite’s color may change, but its streak is always the same

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Cleavage Planes Fluorite, halite, and calcite all have cleavage along flat planes

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Conchoidal Fracture Sulfur has conchoidal fracture, meaning it breaks unevenly

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals A mineral’s resistance to scratching it is called hardness

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Hardness is measured using Mohs’ hardness scale

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Density is another property used to identify minerals

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals More ping-pong balls than golf balls are needed to balance the scale

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 Identifying Minerals Which are more dense, golf balls or ping-pong balls?

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 From Minerals to Rocks Minerals of Granite Rock is a solid mixture of crystals of one or more minerals

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 From Minerals to Rocks Coal Limestone Some types of rock, such as coal and limestone are made of organic materials, not minerals

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 The Rock Cycle The rock cycle is the continuous process by which new rock is formed from old rock material

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 The Rock Cycle Each type of rock can be changed into every other type of rock

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 The Rock Cycle

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 2 Igneous: Rock From Magma What are some positive and some negative effects that volcanoes have on the people and places around them? What Do You Think?

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 2 Igneous: Rock From Magma Lava Fountain All igneous rock starts out as magma inside the earth

© Fall 2005, Pflugerville ISD, 8th GradeUnit A : Chapter 1 : Section 1 Igneous: Rock From Magma Lava “Freezes” into Igneous Rock When magma or lava cools down enough, it becomes igneous rock

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 2 Igneous: Rock From Magma Intrusive Rock- Granite When magma cools beneath the earth’s surface, it forms intrusive igneous rock

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 2 Igneous: Rock From Magma Intrusive Rock- Granite Magma is insulated by the surrounding rock and cools very slowly

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 2 Igneous: Rock From Magma Intrusive Rock- Granite Large crystals form, and intrusive rock has a coarse texture

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 2 Igneous: Rock From Magma Extrusive Rock- Obsidian Igneous rock that forms on the earth’s surface is called extrusive

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 2 Igneous: Rock From Magma Extrusive Rock- Obsidian Extrusive rock cools quickly and does not have time to grow large crystals

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 2 Igneous: Rock From Magma Extrusive Rock- Obsidian Extrusive rock has a fine- grained texture

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 3 Sedimentary: Rock From Other Rocks How are layers of sedimentary rock similar to the rings in a tree? How are they different? What can geologists learn from studying sedimentary rock layers? What Do You Think?

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 3 Sedimentary: Rock From Other Rocks Wind, water, ice, and pressure all cause rock to break into pieces

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 3 Sedimentary: Rock From Other Rocks Rivers Transport Sediment In the process of erosion, rivers move sediment from one place to another

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 3 Sedimentary: Rock From Other Rocks Sedimentary Rock Layers Finally, the sediment is deposited in layers

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 3 Sedimentary: Rock From Other Rocks Sedimentary Rock Layers After compaction and cementation, sedimentary rock is formed

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 3 Sedimentary: Rock From Other Rocks Calcite Flowstone Chemical sedimentary rock forms when minerals crystallize out of a solution of minerals and water

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 1 From Minerals to Rocks Coal Limestone Organic sedimentary rocks such as coal and limestone form from the remains of living things

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 4 Metamorphic: Cooked Rock When you mix up cookie dough, the mixture of ingredients is similar to sedimentary rock. How does the cookie dough change when you place it in a hot oven? What Do You Think?

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 4 Metamorphic: Cooked Rock Contact Metamorphism Metamorphic rocks are rocks that have been changed by heat and pressure

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 : Section 4 Metamorphic: Cooked Rock

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 Let’s Review! What are the five characteristics of a mineral? How is a mineral different from a rock?

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 Let’s Review! How does the rate of cooling affect the size of crystals in igneous rocks?

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 Let’s Review! How does clastic sedimentary rock form? How does chemical sedimentary rock form?

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 Let’s Review! What changes occur when heat and pressure are applied to a rock? What kinds of rocks can become metamorphic?

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter

© Fall 2005, Pflugerville ISD, 8th GradeUnit 3 : Chapter 15 Pre-AP Extensions