Investigation #3 IT’S ROCK TIME STARRING Basalt Limestone Marble & Sandstone
Investigation # 3 Materials needed 1 FOSS tray 4 sticky notes Small basalt Small limestone Small Marble Small Sandstone
ROCK TIME Each group member will select a rock and write the name on it on both sides of the sticky note. (basalt, limestone, marble, sandstone) What would a geologist do given four new rocks to study? On page 10 of the Earth Materials Booklet record your observations of each rock.
All of the samples are rocks. Now come and get a sample of one of the minerals we used from the last test. Can you name the mineral? CALCITE
What is cool about Calcite? Each group needs 5 vials, a syringe, and a container of vinegar Put the calcite in a vial Carefully add 25ml of vinegar to the vial with the calcite. Observe and record what happens on page 11.
Which rocks do you think contain calcite? Put the four vials into the corner sockets in the FOSS tray Put one rock sample in each vial. Carefully add vinegar to each vial until the level is about 1 cm from the top(25 ml) Observe and record what happens.
REPORT RESULTS Put a check next to the rocks that you think contain calcite. Do we need another test? Let’s let them sit overnight and then check them for more clues.
HOW WILL YOU KNOW? If something is left in the dish after the liquid has evaporated, how will you know it is evidence that calcite was in the rock and not just something else?
PART 2 Materials needed Each group needs their FOSS tray 6 evaporation dishes Plastic cup with vinegar syringe Two new sticky notes
Set up the investigation Put vinegar only in one dish and label Put the liquid from the calcite vial into another dish and label. (These are your controls. Follow the same procedure for the rock vials. Clean up.
LOOKING FOR EVIDENCE Observe the dishes being careful not to break any deposits. Compare the rock deposits to the calcite and vinegar. Draw your observations on page 12 of your Earth Materials Notebook. Share observations
Looking for evidence Did you find a deposits of white crystals in the calcite, limestone, and marble dishes? Is there just a slight residue in the vinegar, basalt, and sandstone dishes. Did you notice the needlelike crystals?
DISCUSSION TIME Where did the calcite in the dish come from? How long did it take the calcite to dissolve? Would limestone and marble be affected by acid rain? Would these rocks erode faster or slower if the rainwater did not contain acid?
Effects of Acid Rain on Buildings and Monuments
Rock Types Basalt: a dark, fine-grained rock that began as molten lava extruded from a volcano or rift and then cooled quickly on the earth’s surface. Granite: an igneous rock that forms when magma (molten rock) forms deep in the Earth’s crust. Limestone: one common sedimentary rock – has a wide variety of colors, textures, & origins and consist mostly of mineral calcite. They form where water is present. Marble: a metamorphic rock, is limestone that has been altered by heat & pressure – usually white by tinted by other minerals – often used as columns or countertops Mock rock: forms from common ingredients found in your kitchen (flour, salt, water, food coloring, & alum) and neighborhood (sand, gravel, & shells) - resemble concrete Sandstone: a sedimentary rock formed when rocks such as granite are eroded by wind, water, & ice – used as a building stone.