Add to the chat any "cycles" in science that you have studied.

"Cycle" describes something that goes around over and over. Scientists often use the word cycle to describe patterns in nature that end where they began.

Remember the Law of Conservation of Mass - Matter cannot be created or destroyed. All matter on Earth has been here since its creation and cycles through Earth's systems.

Your kit contains 12 unique rocks, but each falls into one of three types of rocks based on how they were formed.

• igneous

• sedimentary

• metamorphic

GET OUT YOUR ROCK KITS AND LET'S SEE WHAT TYPES OF ROCKS YOU HAVE.

Review video page 3 in edio

Igneous Rocks

• Forms when melted rock cools and hardens.

• Lava - melted rock above ground cools quickly (small or no crystals).

• Magma - melted rock below ground cools slowly (large crystals).

Look at your igneous rocks. Which were formed from lava and which from magma?
How do you know?

1. Obsidian

2. Granite

3. Basalt

4. Pumice

5. Rhyolite

• Formed by gravity pressing fragments of other rocks and minerals together. They are eventually cemented together.

• OR, by materials left behind after the evaporation of water.

Sedimentary Rocks

Look at your sedimentary rocks.

6. Shale (c)

7. Travertine (e)

8. Sandstone (c)

9. Conglomerate (c)

10. Limestone (e)

Metamorphic Rocks

• Formed from previously existing rock by the action of intense heat and pressure.

• The minerals in these rocks change their structure, but they do not melt.

Look at your metamorphic rocks.