It Rocks!Rocks and the

Rock Cycle

A rock is a mixture of minerals, rock fragments, volcanic glass, organic matter, or other natural materials.

What do you see in this sample of pink granite?

Just what are rocks?

What is the difference between a rock & a

mineral? Minerals are solid,

naturally occurring, inorganic, have a fixed composition and are made of one or more elements.

Rocks are made of one or more minerals.

Let’s Compare…

Must be inorganic

Made of elements or

compounds and must be

chemically bonded

Naturally occurring

Made of elements

Solid

Can be made of

lava/ magma

Have crystals

Can be formed

from solutions

Can be made from

organic materialsMixtures made of minerals

Can be man made

Rock

Classifications Igneous

Sedimentary

Metamorphic

Igneous Rock

Igneous is Greek and means ‘born of fire’

Igneous rock forms when magma, hot molten rock, cools and hardens

Igneous rock can be intrusive or extrusive

Intrusive Igneous

Rock Formed from

magma cooled below the Earth’s surface

Cools very slowly Forms mineral

grains large enough to see with the unaided eye

Extrusive Igneous

Rock Formed as lava cools

on the surface of the Earth

Cools quickly Exposed to air and

water which can result in holes in the rock material

Forms very fine (small) mineral grains.

Extrusive Igneous

Rock Includes Volcanic

Glass Lave cools very

very quickly Few or no

minerals grains form

Atoms are not arranged in an orderly pattern

Sedimentary Rock

Forms when sediments are pressed and cemented together

Forms when minerals form from solutions

Often form layers If undisturbed by

nature, the oldest and first layer is the bottom layer

Sedimentary Rock

Sediments are loose rock fragments, minerals grains, and bits of shell that have been moved by the wind, water, ice or gravity.

Sediments form from the processes of weathering and erosion

Compaction – occurs when pressure on the uppers layers of the sedimentary rock pushes down on the lower layers.

Cementation – the process by which water and dissolved minerals move through open spaces and form a glue-like substance

Metamorphic Rock

Metamorphosis – to change

Rocks that have changed their chemical composition due to the presence of extreme heat and pressure or

Rocks that have been subjected to hot watery fluids

Metamorphic Rock

Can form from igneous, sedimentary or other metamorphic rock

Can be foliated - mineral grains appear in parallel layers

Can be nonfoliated – mineral grains do not align in layers

To show how rocks slowly change through time, scientists have created a model called the rock cycle.

It shows the processes that form and change rocks.

The rock cycle shows the three classifications of rock— igneous, metamorphic, and sedimentary—and the processes that form them.

The What?...The Rock Cycle

The Rock Cycle explains how Rocks and Natural Processes

are relatedweathering

melting

pres

sure

, hea

t

Sedimentary Metamorphic

Igneous

Law of conservation of matter

states that matter cannot be created or destroyed.

The changes that take place in the rock cycle never destroy or create matter.

The elements are just redistributed in other forms.

What is the law(principle) of conservation of

matter?

Let’s Have Some

Fun!!

http://tinyurl.com/yzvw4k8

http://mrhardy.wikispaces.com/Rock+Cycle.swf

http://tinyurl.com/8g2fr6f (Study Jams – really great site)

More Fun with the Rock Cycle

Prepared just for YOU, my 6th Grade Earth Science classes!

Ms. HoustonAustin Road Middle School