Earth Materials

1. Earth Materials Investigation 3 Calcite Quest Part 1 – Detecting Calcite

2. For the Teacher – Getting Ready • Put a sample of each rock on the rock identification sheet for students to refer to. • Pour vinegar into cups at the groups’ tables so students don’t have to carry full cups. • Label four half-liter containers with basalt, limestone, marble, and sandstone. • A fifth half-liter container will be unlabeled and contain small calcite samples.

3. For the Teacher – Getting ReadyStudent Materials • 1 FOSS tray • 5 Vials, 12-dr. (no caps) • 1 Syringe • Rock Samples • basalt, limestone, marble, sandstone, calcite • 2 hand lenses • 5 sticky notes

4. For the Teacher – Getting ReadyClass Materials • 5 ½ liter containers • 4 sticky notes • 8 plastic cups • vinegar, white • paper towels • Rock reference set • Rock Identification Sheet • Assessment Chart

5. What We Will Learn • Rocks are made of minerals. • Calcite is one of the most common minerals on Earth. • Putting acid on a rock is a tool geologists use to identify calcite.

6. Science Vocabulary • Basalt, limestone, marble, and sandstone are all rocks. • Calcite is a mineral. • Vinegar is an acid that can be used to test for calcite.

7. Detecting Calcite • How can we tell if one of the ingredients in a rock is the mineral calcite? • We are going to investigate these rocks looking for calcite: • basalt • limestone • marble • sandstone

8. Geological Study – 10 minutes • What is the first thing a geologist would do if he had four new rocks to study? • Yes, record observations. • Materials Getters – get the rock samples and hand lenses. • Record your observations of the rock samples on page 10 in your Earth Materials Notebook.

9. Reporters - Share Observations5 minutes • What is the difference between a rock and a mineral? • A rock is made up of many minerals. • A mineral is made up of only one material. • Rocks are made of many ingredients; minerals are the ingredients in rocks. • The basalt, limestone, sandstone, and marble are all rocks.

10. New Material • Next you will get a sample of one of the minerals you used in the Scratch Test. • Materials Getters please get a sample of the material in the unlabeled container. • Can you name the material? • You may use pages 8 and 9 of your Earth Materials Notebook to help you. • Yes, this is calcite.

11. Calcite • Your sample is the mineral calcite. • This is one of the most common minerals on Earth’s surface. • Calcite is an ingredient in a number of different kinds of rocks. • The first four earth materials you observed today are rocks. • Let’s see if the mineral, calcite, is an ingredient in any of these four rocks.

12. Calcite’s Unique Property • Calcite has a property that no other mineral has. • It reacts with cold acid. • A field geologist often carries a small bottle of hydrochloric acid to test rocks for calcite. • Because hydrochloric acid is dangerous, we will test rocks for calcite with a less concentrated acid, vinegar.

13. Procedure • Put the calcite sample in a vial. • Carefully add vinegar to the vial with the calcite. • Observe and record what happens on page 11 of the Earth Materials Notebook. • Getters get an empty cup and a vial. • I will give each group some vinegar. • Managers should fill the vial to about 1 cm from the top.

14. Observations • Record your observations on page 11 of your Earth Materials Notebook. • From the observations you made earlier, which of the rocks do you think might have calcite as an ingredient? • There is no way to tell just by observing. • What could you do to find out for sure if there is calcite in any of these rocks? • Yes, we can put them in vinegar and watch for bubbles.

15. Bubbles • You will see two different kinds of bubbles. • The bubbles from the calcite and acid reaction are continuous and tiny, and form strings. • Air-pocket bubbles are bigger and not continuous. • Air-pocket bubbles may cling to the surface of the rock for a time before ascending.

16. Calcite Quest • Materials Getters get 1 FOSS tray and four vials. I will give you the vinegar. • Each student will put one of the four vials into a corner socket in the FOSS tray. • Each student will put one rock in a vial. Be sure to keep the rock label with the vial. • Each student will add vinegar to one of the vials until it is about 1 cm. from the top. • Record your observations on page 11.

17. Reporters – Share Observations • Which rocks do you think contain calcite? • Put a check next to the rocks that you think contain calcite. • We may need to do another test to be sure which rocks contain calcite.

18. Further Tests • We will let the vials sit overnight and then observe them for further clues. • Identify your tray with a sticky note. • Materials collectors will VERY CAREFULLY carry the trays to me for stacking on the window sill.

19. Content/Inquiry • Why are we testing for calcite in several rocks? • Calcite is one of the most common minerals on Earth. • Why use vinegar to test for calcite? • Calcite is the only mineral that bubbles when it comes in contact with cold acid.

20. What We Learned • Rocks are made of minerals. • Calcite is one of the most common minerals on Earth. • Putting acid on a rock is a tool geologists use to identify calcite.

21. Literature Connection • Old Man and the Rock: A Native American Tale