Earth MaterialsSCRATCH TEST

Lori Mitchell

We are the Rock Hounds

Been looking for cluesTime after time

Hounded volcanoesSearching the old minesFound plenty of rocks

And minerals tooI’ve found my share of rocks and

graniteAnd I’ve sifted through

We are the rock hounds – my friendsAnd we’ll keep on searching – till the

endWe are the rock houndsWe are the rock hounds

No time for snoozersCause we are the rock hounds

Of the world

OBSERVING MINERALS

Each Group needs:

• a FOSS tray

• two hand lenses

• 4 sticky notes

• 4 Page 8 of Earth Materials Booklet

• 4 Student sheets “Mineral Properties”

Mineral Properties

• Each student will practice identifying simple properties and how to handle two properties at one time by filling out the Mineral Properties sheet.

• Discuss results

Observing Properties

• Number the sticky notes 1-4 and place them in the compartments of the FOSS tray.

• Student 1 will pick up mineral 1 and place it in the group tray compartment labeled number 1.

• Students 2 will pick up mineral 2, and so on.

Observing Properties

• Observe the minerals carefully using your hand lens. (Be careful not to mix them up)

• Record your observations on page 8

• Remember to write observations so detailed you would be able to identify each mineral from your notes, if the numbers were taken away.

SHARING OBSERVATIONS

• Share observations with the class.• Can we identify your mineral from your notes?• Which of the properties is most useful in helping you

identify a certain mineral?• Is one property enough information to identify a mineral?• What if I gave you the clue “It’s a small mineral.” Would

that be enough information to identify any sample of that mineral?

• Do you think you could identify each mineral on another group’s tray if you didn’t have the numbers to help?

Wrapping it Up

• What is a mineral?

• What is the difference between a rock and a mineral?

• If someone sent you a letter and said they needed your help to identify a mineral that they had found, and they told you it was about the size of your fist would you be able to identify it?

Mineral #1

Mineral #2

Mineral #3

Mineral # 4

Scratch Test

• Gather materials:• Tray containing the 4

minerals,• hand lenses,• pennies, • paper clip,• chalk, • tile

CLUE: Quartz is white

HOLD UP QUARTZ

Scratch Test

• Try to scratch a piece of chalk and the tile with the paper clip

• Use your finger to rub away any dust or surface marks

• Use a hand lens to check for a scratch

• Test the tile and the chalk.

• Which tool is harder, the paper clip or the penny.

CLUE #2

• I read that quartz is the hardest of the common minerals on earth. Will that information help you identify the quartz sample in your set?

• You might want to start with the hardest tool.

Looking For Gypsum

• Clue: It is the softest of the 4 minerals.

• Use your scratch tools to identify it.

Record Information

• You will need page 9 of your Earth Materials booklet.

• Write in Quartz for #2

• Write in Gypsum for # 3

• Fill in the appropriate information

Mineral

Tool How many tools could

Scratch this mineral?

Paper clip

Penny Fingernail

1

2Quartz No No No 0

3Gypsum yes yes yes 3

4

Calcite and Fluorite

• CLUE: Fluorite is harder than Calcite

• What do you already know about these minerals from the tests you have already done?

• Which scratch tool might give you the best information at this time?

• How could you find out which was harder if you didn’t have any scratch tools?

Mineral

Tool How many tools could

Scratch this mineral?

Paper clip

Penny Fingernail

1. Calcite

Yes Yes No 2

2Quartz No No No 0

3Gypsum yes yes yes 3

4. Fluorite Yes No No 1

ORDER OF HARDNESS

• Gypsum

• Calcite

• Fluorite

• Quartz

Ordered from softest to hardest

FOLLOW UP

• What do we mean when we say a mineral has a certain hardness?

• If you didn’t have any tools, how could you learn if one mineral was harder than another?

CALCITE

• A common mineral & chemical composition is calcium carbonate. It can be scratched with a penny

QUARTZ

• one of most common minerals and is made up of silicon and oxygen

GYPSUM

A mineral that forms when seawater evaporates under arid conditions

FLUORITE

Is found in a variety of colors-white, green, blue, & violet. It can be scratched with a gym clip.

Mohs’ Numerical Mineral Scale

Talc

Gypsum

Calcite

Fluorite

Apatite

Orthoclase

Quartz

Topaz

Corundum

Diamond

Talc is the softest mineral-1

Diamond is the hardest mineral - 10

Bibliography

•www.fossweb.com

http://www.windows.ucar.edu/earth/Atmosphere/images/acidrain_sm.jpg

http://images.google.com/imgres?imgurl=http://www.dec.ny.gov/images/environmentdec_images/1656acidrainstone.jpg&imgrefurl=http://www.dec.ny.gov/environmentdec/18654.html&usg=__Lv0W6RpsLodmeRpVdAErcbOJYSA=&h=384&w=252&sz=62&hl=en&start=205&tbnid=PuW5MzTrBL62gM:&tbnh=123&tbnw=81&prev=/images%3Fq%3Dacid%2Brain%26gbv%3D2%26ndsp%3D20%26hl%3Den%26safe%3Dactive%26sa%3DN%26start%3D200