Access Prior KnowledgeLesson 5: How are Minerals Identified?

Opening ActivityOpen Science textbook to page 276.Open Science workbook to page 90A to review home learning.Open Science folder to review vocabulary words and outline for the chapter.Open Science journal and answer the following questions:

 1. How are mechanical and chemical weathering the same and  different?

Review Content Cards and Q-Cards in bin, sharing with partners quizzing each other quietly.Log in to clickers using student ID number.Be ready to review home learning when timer goes off.

Don't forget to write your home learning in your agenda page 92A.

1 You can find minerals in the rocks and soil of Earth.

Yes

No

Do you agree with the statement?

2 All minerals have the same level of hardness.

Yes

No

Do you agree with the statement?

3 You can classify minerals by how shiny they look.

Yes

No

Do you agree with the statement?

4 Scientists have already identified every mineral that exists on Earth.

Yes

No

Do you agree with the statement?

Properties of Minerals

A mineral is a natural solid whose particles make a pattern. Soil and rocks are made of minerals.There are many different minerals. However, only a few dozen minerals make up most of the rocks on Earth. Every mineral has certain properties. Minerals can give off a sweet, earthy smell, or a rotten egg smell. Some minerals make tiny bubbles when they touch chemicals called acids.

Hardness: Some minerals are harder than others. The Mohs scale is used to tell how hard a mineral is. The scale rates the hardness of minerals from 1 to 10. Talc is the softest mineral. It has a hardness of 1. Diamonds are the hardest minerals. They have a hardness of 10.Magnetism: Some minerals have magnetic properties. Pyrrhotite and magnetite are minerals that are strongly magnetic.Luster: Luster is the way a mineral’s surface reflects light. A mineral’s luster can be glassy, earthy, metallic, waxy, silky, or pearly.Shape: Not all minerals have specific shapes. But pyrite, for example, is shaped like cubes. A mineral’s shape will cause the mineral to break in specific patterns.Streak: Scientists rub minerals on a hard, rough, white surface. This makes a powder. The color of the powder is a mineral’s streak. A mineral’s streak is usually different from the minerals outside color.Texture: Texture is how a mineral feels. A mineral’s texture might be sandy, sticky, smooth, or powdery.

Properties of Minerals

Scientists record the properties of unknown minerals. Then they compare these observations to minerals they have already studied.

Using Properties to Identify Minerals

Mineral Identification

MatchQuest

This mineral has a gritty texture and dull to glassy luster. It smells like a rotten egg and has a white streak.

This mineral has a smooth texture, no smell, and a glassy luster. Its hardnessis 4, and its streakis white.

This mineral has a greasy texture and a pearly luster.Its hardness is 1, and it has a white streak.

This mineral has asmooth texture and a pearly luster. Its hardness is 2.5, and it forms sheets.

This mineral has a smooth texture, a hardness of 2.5, and leaves a white streak. Its luster is glassy.

This mineral has agritty texture and a metallic luster. It smells like garlic,has a hardness of 5.5 to 6, and it hasa black streak.

Florite

Talc

Sulfur

Muscovite Halite

Arsenopyrite

Use the chart on page 284 to identify minerals.

TextQuest

1. What is a mineral?

2. What properties are used to identify minerals?

3. How is a mineral's streak determined?

Don't forget to write your home learning in your agenda page 92A.