Chapter 7: The Rock Cycle Teacher Imarlys Cajigas 5th grade Science

Lesson 1: What are Minerals? A mineral is a naturally occurring, nonliving solid that has a specific chemical makeup and a repeating structure. Scientists use minerals properties to identify and classify them. Common Properties Unique Properties Color Double Image Luster Magnetic Streak Fluorescence Hardness Electrical charge

Properties Streak- the color of the powder left behind when you rubbed a mineral against a streak plate. Streak is a better property than color because the streak does not vary. Luster- the way a mineral’s surface reflects light. Luster can be metallic or non metallic (dull, glassy, pearly, or waxy).

Review What are minerals? What are some common properties of minerals? What are some special properties of minerals? Which mineral property is better for identifying a mineral: magnetism or hardness? Which of the following mineral properties can be expressed by a number? A- color B- hardness C- luster D- streak

Lesson 2: How do Rocks Form?

Rocks A rock is a natural solid made of one or more minerals. Rocks are classified into three groups depending on how they form.

Igneous Rocks Rock that forms when melted magma cools and hardens. They can form underground or on Earth’s surface. When melted rock cools slowly the crystals are bigger, when it cools quickly it has small crystals or no crystals. Igneous rocks contain different amount of minerals and silica depending on where they formed.

Igneous Rocks Basalt Pumice- has lots of air spaces and is very light. Obsidian – is also called volcanic glass. Basalt- is the most common igneous rock. Gabbro- is used to make concrete.

Sedimentary Rocks How they form? Rocks are worn away by wind, water, or ice. Sediments are carried and deposited in another place. Sediments settle out of water or dropped by wind in the process of deposition. Over time sediments pile up on layers, minerals form a kind of cement that stick them together and form rocks called Sedimentary Rocks!

Sedimentary Rocks Some contain big pieces of sediments, other have remains of living things. sandstone conglomerate limestone shale

Metamorphic Rocks When rock is changed by heat and pressure, metamorphic rocks form. Metamorphic rocks are found on every mountain range on Earth and near some volcanoes.

Metamorphic Rocks Gneiss Schist Quartzite Slate Marble

How rocks are used? To make tools, sand paper, and surgical instruments. Sandstone, Granite, Marble, and Limestone to build monuments. The Capitol in the US (sandstone and marble) Giza Pyramid in Egypt (sandstone and limestone) To make cement, glass, gravel, and other building materials. The minerals from rocks are used in products such as cell phones, cars, and computers.

Lesson Review How do rocks form? How can different kinds of igneous rocks be classified? How do sedimentary rocks form? What are some kinds of sedimentary rocks? What causes metamorphic rocks to form? What do you think is the most common use of rocks? What kind of rock is gneiss? A- igneous B- marble C- metamorphic D- sedimentary

Lesson 3: How are rocks changed?

Processes that change rocks Weathering- the process of wearing away rocks. Rocks that contain hard minerals weather slowly, while rocks that contain soft minerals such as talc weather faster. Erosion- is the process of moving sediments by wind, water or ice.

Soil Formation Soil comes from weathered rocks. The kinds of minerals found in any soil depend on the kind of rock from which the soil formed. Rich farming soil contains small pieces of decayed plants and animal matter, called humus which provides additional nutrients that plants need to grow.

Lesson Review How are rocks changed? What determines how quickly a rock is weathered? How might a sedimentary rock change into another sedimentary rock? Which of the following processes can change a metamorphic rock into a sedimentary rock? A- adding pressure B- increasing temperature C- melting D- weathering