ROCKS. Minerals are the “building blocks” of rocks There are more than 3,500 different minerals...

ROCKS

Planet Earth – Topic 2

Minerals are the “building blocks” of rocksThere are more than 3,500 different

minerals on EarthBut, most rocks are made up of the

same 5 minerals:CalciteQuartzFeldsparMicaHornblende

Rocks vs. Minerals

ColorLustre Streak CleavageFractureHardness

Properties of Rocks

Moh’s Hardness Scale

1. Igneous Rocks Formed when hot, molten rock

(magma) cools and hardens Intrusive rocks form under the Earth’s

crust as magma cools Extrusive rocks form when lava cools and

hardens on the Earth’s crust Basalt is the most common type of

igneous rock

The 3 Types of Rocks

The Devil’s Tower

2. Sedimentary Rocks Formed when small pieces of rock are

carried by water or wind and settle onto the bottom of rivers, lakes, or land

As the layers pile on, time and pressure cause the layers to harden

The bottom layer is the oldest, and the top layer is the youngest

The 3 Types of Rocks

Sandstone

3. Metamorphic Rocks Rocks that have been changed These rocks were once igneous or

sedimentary, but the intense heat and pressure within the Earth changes the appearance of the rock

Marble is a common example of this type of rock

The 3 Types of Rocks

Marble and Quartzite

Turn to page 382 in your textbook, and look over the “Rock Summary Table” on that page

Draw the charts seen on page 383 in your notebook and use the rocks and tools provided to determine the type of rocks you analyze

Can You Tell the Difference?

Just like the way you and I recycle bottles, paper, and other wastes; the Earth recycles too!

The Earth recycles rocks A rock will undergo several

changes over time, and can fit into each rock type over time

The Rock Cycle

The Rock Cycle

Cooling, Erosion, Pressure, Intense Heat and Pressure, Melting