Rocks, Minerals and Soil Third Grade Earth Science

Rocks, Minerals and Soil

Third Grade

Earth Science

What are rocks?

• Rocks are solid materials that are made of one or more minerals.

3 Types of rocks

1. Sedimentary

2. Igneous

3. Metamorphic

Metamorphic Rock

• Metamorphic rock is rocks that have been changed by heat and pressure.

Metamorphic Rocks

Sedimentary Rock

• Sedimentary rocks form when materials settle into layers and harden.

• Any rock can become sedimentary if at the surface.

Igneous Rock

• Igneous rock is a rock that was once melted but has cooled and hardened.

• Hot lava comes out from within the earth and is an igneous rock once cooled.

4 ways to identify rocks

1. Texture

2. Color

3. Size

4. Hardness

EXPERIMENT TIME!!!

• You are all now junior geologist. A geologist is someone who studies the Earth. We will test the hardness of rocks using Moh’s scale.

Moh’s Hardness Scale• With your group, test the

hardness of rocks and give it a score of 1 to 10.

• Soft: scratches with fingernail 1 or 2

• Medium/Soft: scratches with a penny 3 or 4

• Medium/Hard: scratches with a nail 5 or 6

• Hard: will not scratch 7 or 8

Moh’s Scale

• Working as a group, make a bar graph with your group rating your rocks from softest to hardest. Be sure your graph is labeled and colorful.

Classify rocks

• As a group, discuss classifications of your rocks. Remember the 4 ways to classify rocks.

1. Color

2. Size

3. Texture

4. Hardness

What are minerals?

• Minerals are solid natural made objects that have never been alive. Minerals can be rock-like or metals.

How are rocks and minerals different?

• Rocks are made up of minerals. Minerals are within all rocks. The minerals in rocks are what makes rocks look different from other rocks.

Rocks and Mineral

Minerals Rocks

Usually very pretty Not pretty

Has a shape No shape

May contain crystals No crystals

Will not contain fossils May contain fossils

Color is mostly the same May have many colors

Identify the Minerals

Time to Play a Game…. How many minerals can you find in the kitchen? (click on refrigerator)

What are fossils?

• A fossil is a mark or the remains of something that was once living.

4 Types of Fossils

1. Mold

2. Cast

3. Trace

4. True-form

Mold Fossil

• A mold fossil is a impression made in a substance. It is not the actual living organism but a impression.

• The picture is a mold fossil of a leaf.

Trace Fossil

• Trace fossils are impressions like mold fossils but are not the actual living organism- just evidence of them.

• Examples: nests, burrows, and footprints.

True-Form Fossils

• True form fossils are the actual once living animal or organism.

• Example: Animal bones

Cast Fossil

• A cast fossil is formed when a mold fossil is filled in. The fossil can be of anything that once lived (plants, animals, insects).

Types of Soil

1. Clay

2. Sandy soil

3. Potting soil

4. Loam

Clay

• Clay is smooth when dry and sticky when wet. Soils high in clay content are called heavy soils. Clay also can hold a lot of nutrients, but doesn't let air and water through it well.

Sandy Soil

• When you rub sand, it feels rough. This is because it has sharp edges. Sand doesn't hold many nutrients.

Loam

• Loam is a mixture of different types of soils. Loam soils feel smooth and spongy when rolled into a ball.

Potting Soil

• Potting soil is soil mixture made for use in gardens and potted plants. Potting soil should be loose and light.