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.
For the Teacher – Getting Ready Student 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
For the Teacher – Getting Ready Class Materials 5 ½ liter containers 4 sticky notes 8 plastic cups vinegar, white paper towels Rock reference set Rock Identification Sheet Assessment Chart
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.
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.
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
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.
Reporters - Share Observations 5 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.
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.
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.
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.
Procedure 1. Put the calcite sample in a vial. 2. Carefully add vinegar to the vial with the calcite. 3. 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.
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.
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.
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.
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.
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.
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.
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.
Literature Connection Old Man and the Rock: A Native American Tale