Chapter 9

1. Chapter 9 Rocks and Minerals 6th Grade Science

2. Minerals • ___________ - a natural, non-living solid with a definite chemical structure. • Earth’s crust contains more than _________ minerals – only two dozen are common. • Examples: diamond, quartz, emerald copper • Minerals are made up of ______. • Particles of _______ are arranged in a particular repeating pattern. Mineral 4,000 kinds crystals crystals

3. Crystals • _______ form when minerals are made in nature • Each type of mineral has its own unique chemical __________. • Differences in minerals result from the way that particles are arranged. • Brass – Copper + Zinc –____________because it does not occur naturally Mineral structure Not a mineral

4. Identifying Minerals • _________ • _________ • ____________ • __________ • ___________ hardness Streak color Shape of crystals cleavage Luster

5. Identifying Minerals • Minerals are identified by their ____________ • _______________ - a scale to measure hardness of a mineral • The range of the harness scale is from 1 (_______) to 10 (______) • Talc has a harness of __ / diamond is a _____ • ________ - refers to how difficult it is to scratch its surface characteristics Moh’s hardness scale Softest Hardest 1 10 hardness

6. Other Mineral Characteristics • _______ - a mineral may have different crystals depending on the kinds of materials that make up its ______. • The color of a mineral can be seen in its ______. • A mineral can also be identified by the ______ of its crystals. • _______ - minerals show particular patterns when they are broken along flat planes. Color crystals streak shape Cleavage

7. Luster • ______ - the appearance of a mineral in reflected light. • A mineral may appear: • __________ • __________ • __________ • __________ • __________ Luster Metallic Nonmetallic Greasy Glassy Waxy

8. Value of Minerals • Some minerals are ____ which makes them very valuable • Some minerals are valuable because they are ______________ - scientists have tried to find ways to reuse minerals or replace them with less expensive materials. • Aluminum and tin can be ________ • Synthetic forms of gemstones = cubic zirconia rare Natural Resources recycled

9. Assessment • Page 249 questions 1 and 2

10. Rocks • _____ - a solid, natural material made up of one or more minerals • ___________ - as time passes, rock break down, and the minerals in them are recycled – pattern of change • The rock cycle takes place over ________ of years. • There are three types of rocks: __________, __________, and __________ rock Rock cycle millions sedimentary igneous metamorphic

11. Sedimentary Rock • ______________ - made from pieces of rocks and minerals • Sedimentary rock forms in ________ - the oldest rock at the bottom and the newest rock on top. • Sedimentary rock is like a “_________” - past events captured in each layer. • _____ - remains of once living animals or plants Sedimentary rock layers History book fossils

12. Sedimentary Rock Continued • Fossils are ONLY found in _____________ • Example of sedimentary rock = ________ • Limestone is made from _________________ or from dissolved __________ that settle out of seawater. Sedimentary rock limestone Shells of tiny sea animals minerals

13. Igneous Rock • __________ - forms from magma – molten rock inside of the earth that cools and hardens • Some igneous rock forms ______________ and is only exposed after rocks above have worn away • Other igneous rocks form when _____ cools at the Earth’s surface • When lava cools fast - _______________ • When lava cools slowly - _______________ Igneous rock Below Earth’s surface lava Fine-ground rocks form Coarse-grained rock

14. Metamorphic Rock • _____________ - forms when heat, pressure, or chemical reactions change one type of rock into another type of rock. • Metamorphic rock is made from ___________ or _________. • Example: ______ is a metamorphic rock made from________ (sedimentary rock) Metamorphic rock Sedimentary rock Igneous rock marble limestone

15. Compare and Contrast • How are the three types of rocks similar and different?

16. Clues to the Past • Scientists can tell a great deal about Earth’s history by looking at _____. • ______________ - scientists look at the layers of sedimentary rock and learn about the relative age of each layer and the minerals found in it. • Relative dating allows scientists to place past events in ____________ rocks Relative dating Sequential order

17. Fossils • ________ - can form when an organisms is buried in soft mud or when parts of the organisms do not rot away. • Burrows and footprints can also be fossilized • Many fossils were made by animals that are now _____ - helps scientists determine the rocks age. • __________ - a fossil of marine animals known as corals fossils extinct Peoskey Stone

18. Assessment • How can rocks help scientists learn about the past? • What are trilobites and when were they on Earth?

19. Soil • ____ - made of weathered rock, air, water, and the remains of living things. • __________ - process of breaking down rocks through physical factors such as _____, _________, _______ or__________________. • ________ = non-living parts of the soil • As rock breaks down small pieces collect on the surface soil weathering frost drought rainwater Changes in temperature inorganic

20. Soil Formation • _______ and _______ are plants that help break down rock. • When rocks are broken down _______are released • ___________ - dead or decaying matter such as bacteria, fungi, animals and plants. • ______ - dark colored organic matter formed from decayed plant and animal remains- _______________________ mosses lichens minerals Organic matter humus Rich in nutrients needed by plants

21. Layers of Soil • Soils form in _____ layers • _________- a vertical cross section of the soil and rock underneath • ________ - first layer of soil, mixture of small rock pieces, humus, and other organic matter • Most living things are found in the _______ • Loose _____________ often covers the topsoil • Rainwater carries minerals from the topsoil to the 2nd layer of soil. three Soil profile topsoil topsoil Organic matter

22. Subsoil / Parent Rock Layers • _______ - less organic matter than topsoil, lighter in color. • _________ penetrate the subsoil through rainwater and accumulate • _________ - third layer, very little organic matter found in this layer subsoil mineral Parent rock

23. Kinds of Soils • ________ - fine grained and hold water – these soils can become waterlogged • _________ - medium sized grains – better drainage than clay soils • __________ - large-grained, do not retain water • Most soils are a mixture • ______ - silt and sand in roughly _____ parts Clay soils Silt soils Sandy soils loam equal

24. Factors That Affect Soil • ________ - most important factor that determines the type of soil that is formed • Climate affects _________ - increased rainfall, warm temperatures, frost-thaw etc. • __________ - minerals in the rocks affect the characteristics of the soil – example: reddish colored soil indicates iron-rich minerals • __________ - mix the soil and breakdown organic matter climate weathering Kinds of rock earthworms

25. Soils Continued • Soil color is affected by the amount of __________ in the soil. • Soils with more organic matter are ______ • ___________ - affects soil formation because of slope and erosion • Mountains have thin layers of ______ • Land that is flat has a _________ of topsoil because of minimal erosion Organic matter darker Shape of land topsoil Thick layer

26. Assessment • Write an advertisement for an ideal soil for growing plants.