4 th Grade Earth Science

1. 4thGrade Earth Science Chapter 8 Rocks and Minerals

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 • 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

5. 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

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

7. 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

8. 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

9. 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

10. 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

11. 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

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

13. 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

14. Rock Cycle