what are rocks made of? minerals are not made by people; they are … …naturally occurring...

What are rocks made of?

Minerals are not made by people; they are …

…naturally occurring substances.

Name four properties (or clues) that scientists use to identify minerals.

Color, luster, streak, and hardness

Which property means the way the light bounces off the mineral?

What words can be used to describe a mineral’s luster?

Glassy, dull, shiny, greasy

Why is color not a good property to use to identify a mineral?

Many minerals have the same color.

slate limestone

What are three testers that can be used to determine a mineral’s hardness?

fingernail, penny, nail

What type of rock is formed when magma cools and hardens?

There are two types of Igneous rocks

Intrusive in side the earthExtrusive out side the earth

Granite is an example of an Intrusive Igneous Rock

It forms under the Earths surface from the cooling of magma

Intrusive igneous are usually rough to the touch unless they are polished

Examples: Kitchen CountersThe Continental Crust of the Earth

is primarily made of Granite

Other examples of Intrusive Igneous Rocks:

Gabbro Andesite Diorite

Examples of Extrusive Igneous Rocks

• Basalt is an example of an Extrusive Igneous Rock

• The Oceanic Crust is made primarily of Basalt – Basalt is formed from lava

on the crust of the Earth. – Because it is formed on the

surface, the crystals are very fine-grained

Other examples of Extrusive Igneous Rocks

Obsidian Rhyolite Scoria

What type of rock is formed when weathering and erosion cause sediments to press together in layers?

Sedimentary RocksSedimentary rocks are formed by the

accumulation of sediments.

Sediments include materials from sand grain size to boulder size

Clastic Sedimentary Rocks

• Clastic Sedimentary Rocks are formed from mechanical weathering debris

• Mechanical weathering takes place when rocks are broken down without any change in the chemical nature of the rocks

Breccia Conglomerate

Sandstone Shale

Chemical Sedimentary Rocks

• Chemical Sedimentary Rocks form when dissolved materials precipitate from solution

Halite

Limestone

Organic Sedimentary Rocks

• Organic Sedimentary Rocks form from the dead plants and animals and their debris.

• Coal and fossiliferous limestone are examples of organic sed. Rock

Fossiliferous Limestone

Coal

What type of rock is formed when change occurs from heat and pressure in the Earth?

Metamorphic Rocks Metamorphic rocks have been modified (changed) by

heat, pressure and chemical process

usually while buried deep below Earth's surface.

There are two basic types of metamorphic rocks: Non-foliated Foliated

Foliated Metamorphic Rocks

• Foliated metamorphic rocks: have a layered or banded appearance known as a foliation

Gneiss

Schist Slate

Non-Foliated Metamorphic Rock

• Non-foliated metamorphic rocks such as marble and quartzite

• do not have a layered or banded appearance

Melted rock below the Earth’s surface is called…

Small bits and pieces of rocks are called…

The breaking down and wearing away of rocks is called…

The movement of sediments from one place to another is called…