Task Sit with rock group. Push desks together. One person brings rock tray to table. GIVE ME YOUR ATTENTION
Investigating the Rock Model
Conglomerate Made of mineral and rock fragments held together in clay or another cementing medium.
Rock Model Ingredients Aluminum Potassium Sulfate Clay Gravel Salt Sand Talc Water Three mystery minerals
How is the process by which you formed your rock different from how rocks form in nature? Rocks form naturally Fused together by extreme pressure and heat Takes thousands of years
Investigating Rock 1.Place rock flat on table 2.Use nail to break apart the rock 3.Separate gravel and sand to one side 4.Find your Fossil and three mystery minerals.
Mineral Tests Luster- how is light reflected Streak- what color is the powder residue? Hardness- does it scratch glass? Acid Tests- do bubbles form when the vinegar is applied to the mineral? Record observations on activity sheet.
Acid Test Background Information Moisture + Airborne Oxides (sulfur and nitrogen)= Acid Rain
Acid rain causes deterioration of buildings, statues, and monuments made from certain kinds of rocks and minerals.
Acid Test Apply a mild acid to a mineral to see if there is a chemical reaction. Used by geologists to confirm the presence of calcium carbonate in rocks. Calcium carbonate reacts with acid to form carbon dioxide gas This gas is evident in the form of bubbles or fizzing.
Calcium Carbonate Chalk Limestone Marble
Calcite Calcium carbonate crystals are referred to as calcite.
Calcium Carbonate Calcium carbonate is the most widely used mineral in the paper, plastics, paints and coatings industries both as a filler – and due to its special white color - as a coating pigment.
Calcium Carbonate Contributes to the making of mortar used in bonding bricks, concrete blocks, stones, roofing shingles, rubber compounds, and tiles.
Calcium Carbonate Calcium carbonate causes a unique reaction with acids. Upon contact with an acid - no matter the strength - it produces carbon dioxide CO 2 This provides geologists with a reliable test to identify calcium carbonate.
This same phenomenon is important to the formation of caves.
Acidic rain water runs off and goes underground where it dissolves the calcium carbonate limestone.
The calcium carbonate water runs down and eventually reaches an air-filled cavity underground where the carbon dioxide can be released.
When it is released, the calcium carbonate crystallizes again. Stalactite and stalagmite formations are created when water containing calcium carbonate drips, leaving some mineral at the source of the drip at the roof of the cave and some where it falls.
Acid Test 1.Place your minerals in the petri dish. 2.Use a mild acid (vinegar) to see if calcium carbonate is present in your mystery mineral. 3.Place 3-5 drops of vinegar on one mineral at a time. Wait and observe. 4.If bubbles/fizzing occurs, then you know calcium carbonate is present.
Exit Slip How is the Acid Test useful for geologists?