Rocks and Minerals

By: JohnnyBook

Sedimentary rocks

• These rocks cover over 80% of Earth’s land area. Most of them are made from pieces of other rocks. When other rocks get worn down by rain the pieces get deposited into seas, rivers, and lakes. They build up over a long time and this squeezes the water out and after they’re dried up it makes a rock. (so that is how most of these rocks get made)

• On the next slide there will be an example

Conglomerate(a type of sedimentary rock)

• This rock is made of left-over rocks. This rock’s lumps and bumps are smooth. Sometimes this rock is only made of one rock. Colors it can be include bright yellow, red, and gray!

Molten Rocks

• These rocks start low beneath the surface of the earth. Then they explode out of volcanoes. When they cool off, they form a solid rock. They make up 95% of the earth’s crust. Many of them contain the world’s most important minerals.

• Some types of molten rocks:– Obsidian– Basalt– Peridotite

• See next page for “Tuff”

Tuff(an example of a molten rock)

• This rock is made mostly of ash.

• It’s colors can be: brown, gray, yellow and red.

• It’s look-alike is called ignimbrite

• It is found in young volcanoes

Metamorphic Rocks

• These rocks start out as one type of rock, but when heated or pressurized they change! These rocks can change so much that they don’t even look like their original rock!

Slate(a metamorphic rock)

• This rock was once clay, mudstone, or volcanic ash. This rock was put under pressure, then it changed. This rock has two layers: made up of the original rock (this layer is called bedding) and the second layer is it’s new form, slate (called foliation). It can split easily on the direction of the layers. This rock can be used for roofing and pool

tables! • Colors: dark gray, green, purple

ORE

• Some examples of this category are steel and copper, which helped build the modern world.

• Some examples include:– Hematite– Magnetite– Pyrite

Uraninite(another type of ore)

• It is radioactive

• It is the principal ore of uranium

• Know one knew it’s value until 1898

• It’s hardness is 4-6

• Colors: Black and brown

Minerals

• There are more then 3*10 of these fellows.

• Each one has it’s own structure.

• These rocks you can find in veins hundreds of feet, some even miles long.

• Some examples:– Quartz– Olivine– Talc

3

Hornblende (a type of mineral)

• This mineral has a German name.

• It is made of silicate

• Looks like Augite

• It’s hardness is 5-6

Purists (or Native Elements)

• These rocks only have one type of atom in them, which is why they are called “purists”, or elements.

• Nothing can be simpler then these rocks.

• These make up the periodic table.

• Some of these rocks make the finest ore and the worlds greatest treasures.

• Examples: Gold, Graphite, Sulfur

SILVER(a purist)

• It can be found mixed with GOLD, sulfur, and arsenic.

• This rock, as you should know, is minted as coins and used for jewelry.

• Bacteria and fungi can’t stand it, so it is used to help wounds heel!

Little Gems

• There are only 130 gems in this group.

• When they are cut and polished they become gem stones.

• They are rated on the four C’s : color, cut, clarity, and carat (weight).

• Examples:– Emerald (beryl)– Jade

DIAMOND(a gem)

• Since this is the hardest mineral on earth it is resistant to chemicals and it never gets scratched or nicked.

• Diamonds are formed in volcanic pipes but it can be pulled up out of rivers and off into the ocean.

• This mineral is 100% carbon, and it forms nice looking crystals.

• Its hardness is 10

Fossils Fossils dun dun duuun

• These aren’t really rocks or minerals, but fossils hold cool prints of animals, and other cool stuff.

• Fossils are as old as rocks, and they form layers in bedrock that give clues about the past.

• 18th century scientists figured out that fossils contained imprints of organisms that were once living.

Trace fossil

• This fossil captures the activities of ancient animals. The first examples of this guy are slithers by worms 570 million years ago. Dino tracks are this fossils most famous imprints.

Read this book

• This book contains lots of cool information on rocks and minerals. So I strongly suggest you read this book.

The end