Unit C Chapter 2

Mineral Sample Color of Mineral Sample Color of Mineral Streak Things that Scratch The Mineral

 Mineral – is always a solid material with particles arranged in a repeating patters.  The pattern is called a crystal.  Minerals form in different ways, some form in Earth’s mantle, others form on the surface of the Earth.  Minerals can look very different depending on how and where they were formed.

 Streak – is the color of the powder left behind when you rub a mineral against a white tile.  Luster – describes the way the surface of the mineral reflects light  Ex. Aluminum foil has a metallic luster.  Hardness – is a mineral’s ability to resist being scratched.

 Minerals can be used in a variety of ways.  Jewelry  Musical Instruments  Electric wiring  Pencils  Table Salt

Rock Sample ColorTexturePictureBubbles When Vinegar Added

 Rock – is a material made up of one or more minerals.  There are many different kinds of rocks, and they form in different layers of the Earth.  There are three main categories rocks can be classified in.  Main Types of Rocks 1. Igneous 2. Sedimentary 3. Metamorphic

 Igneous rocks form when melted rock hardens.  Fine-grained – rocks that form from magma that cools quickly. These rocks have small mineral pieces.  Coarse- grained – rocks that form from lava that cools slowly.  Fine-grained  Coarse-grained

 Sedimentary rocks form over a long period of time as they are squeezed and stuck together.  The rocks are made of eroded material that is deposited at the bottom of streams, rivers and lakes.  The largest pieces are dropped first.  Conglomerate – is a type of sedimentary rock that can for from large pieces  Some can pieces can be as large as boulders.  Limestone – is a fine grained sedimentary rock that form in oceans, sometimes even including seashells.

 Metamorphic rocks form under high heat and great pressure that can change a rock.  Metamorphic rocks can form from any kind of rock – sedimentary, igneous, or even other metamorphic rocks.  Metamorphic rocks c an form as mountains are built up. They also form as other rocks are squeeze and heated.  Types: 1. Gneiss 2. Marble 3. Quartzite

1. Which would be a better model of how an igneous rock changes into a sedimentary rock- an eraser rubbed on paper, or crushed graham crackers that are mixed with melted butter and pressed into a pie pan to make crust? EXPLAIN your answer. 2. Which could be a better model of how metamorphic rocks form- chocolate chip cookie dough that is flattened and than baked into cookies, or chocolate chips mixed with butter and melted together in a pan and then cooled to make fudge? EXPLAIN your answer.

 A rock can begin as one type and be changed many times.  Change takes many thousands of years.  This never ending rock change is called the rock cycle.