Rocks and
Minerals Unit
Trinity Clancy
Note: This unit is for my 6th grade ELL students and includes many hands-on activities.
Activity 1:
Describing and Modeling the Formation of Igneous, Sedimentary and Metamorphic
Rock.
Internet link: To see an animation of how the three types of rock are formed go to:
http://www.fi.edu/fellows/payton/rocks/create/
Step One: To simulate igneous rock, we will make fudge.
1 12-oz.
package of semisweet chocolate
3⁄4
cup sweetened condensed milk
Pinch
of salt
1
tsp. Vanilla
Put chocolate pieces in top of a double boiler (use a hot plate and 2 pans if necessary). Melt over boiling water, stirring several times. Remove from heat and add the sweetened condensed milk, the salt, and the vanilla. Stir until smooth. Put into a waxed paper-lined pan. When it cools, it hardens into solid fudge, just as lava and magma cool into solid rocks.
Step Two: To simulate metamorphic rock we will bake brownies. The heat of cooking causes a chemical change in the ingredients. What comes out is very different from what went in. That is very much like what happens to metamorphic rocks. Marble is not much like the limestone that it came from.
Step Three: We’re going to make sedimentary rock by layering pieces
of the fudge and brownies. Since sedimentary rocks are made up of bits of other rocks,
start by crumbling the brownies.
Instead of using water, wind or ice to transport the fragments, we can
use gravity. Sprinkle the crumbled
brownie into a bowl. Sedimentary rocks
usually form layers, so make a layer of brownie fragments. Fudge represents igneous rock, since it is
cooled to make it a solid. Add fudge
fragments until you have a second layer.
Chop
some nuts very fine, to represent sand and gravel or plant matter. Sprinkle a thin layer of the nuts to make
the third layer.
Use
the sedimentary sample to look at the history.
The bottom layer one was put down first. The same is true in geology. This is the Law of Superposition. As long as the layers have not been turned
over or disturbed, the bottom layer is the oldest, newer layers are added to the
top.
The
bottom layer is made up of metamorphic fragments. With a geologic site, that would tell us
that those fragments came from a layer of rock that had been changed by heat
and pressure. We could also tell what
the rock was before it was changed. For
example, slate starts as shale, marble begins as limestone, and quartzite
starts as sandstone.
The
next layer up was fudge, which we said was igneous. But again, it was fragments of the
"rock", so again we know that some older rock has been eroded to form
this layer.
The
top layer is made up of plant material, the nuts. Not all rocks are made of minerals. Peat and coal are both examples of rocks
that are made up of plant material.
Also,
layers can be cut and then offset, to simulate a fault. Or model erosion with a spoon. Then you could simulate a volcanic eruption
with a lava flow of hot fudge.
Step Four: Using the science textbook as a reference, review information about classifying rocks and how rocks are formed. Then examine rock samples, describe each rock using qualitative and quantitative observations. Then classify the rocks as igneous, metamorphic or sedimentary based on the description and the information we have learned.
Step Five: Make a diagram of the rock cycle. If possible use pictures or rock samples in
the diagram.
Internet link: To
view a diagram of the rock cycle and take a quiz on identifying rocks go
to: http://regentsprep.org/Regents/earthsci/rockcycle.htm
Step Six: Assessment: Students are given 3 rock samples and asked to describe, classify and explain their classifications. As an extension they can hypothesize where the sample was found.
Review: See attached worksheet, entitled WALKING REVIEW. Students are asked to find someone who knows the answer to the questions in each box. The goal is to find a different person for each question and to find complete answers for each question.
Activity 2:
The Difference between Rocks and Minerals
Here’s a website with information on rocks and minerals and the difference between them.
http://www.nps.gov/brca/Geodetect/Rocks%20&%20Minerals/RM%20unitpage.htm
This website has more detailed information about the difference between rocks and minerals:
http://www.dnr.state.oh.us/geosurvey/edu/hands11.htm
This website has a lab activity and a simple descriptive worksheet on rocks and minerals:
http://www.msnucleus.org/membership/html/k-6/rc/rocks/1/rcr1_1a.html
Students will use the science text book and the Internet to come up with an explanation about the difference between rocks and minerals. Then they will examine some samples and classify each as a rock or mineral and explain their reasoning.
Students will learn to describe rocks and minerals using attributes such as luster, density, cleavage, color, texture.
More information and attribute information is available here:
http://www.rockhounds.com/rockshop/mineral_id/
Using a card game such as Cinnabar from Ward’s Natural Science Catalog, students can build their vocabulary in describing each of the attributes:
Cinnabar:
A Card Game of Rocks and Minerals
Arranged in groups by their major elements, the 56
full-color cards help students learn how to recognize the individual rocks and
minerals, plus their chemical families. You will also get instructions for five
different games.
Activity 3:
Testing the Hardness of Rocks and Minerals and Learning Moh’s Hardness Scale
In small groups, students are given samples of the main minerals in the Mohs Hardness Scale and their job is to test the samples and sort the minerals in order from softest to hardest. Then, they will make a hardness chart, listing the mineral that corresponds to each hardness number.
Materials Needed: Mineral samples: talc, gypsum, calcite, fluorite, apatite, feldspar, quartz, topaz, corundum (diamond, if possible). Also, copper pennies, nails, streak plates, and magnifying lenses.
Using the hardness scale, students will test the hardness of other rock and mineral samples, and compare their results to the listing in a Rocks and Minerals Guide Book or an Internet site listing.
Some good resource books for identifying characteristics of rocks and minerals are:
·
Encyclopedia of Rocks, Minerals, and Gemstones by Chris Pellant, Henry Russell (Hardcover)
·
DK Handbooks: Gemstones by Cally Hall, et al (Paperback)
·
Smithsonian Handbooks Gemstones by Cally Hall, et al (Paperback)
·
Simon and Schuster's Guide to Rocks and Minerals by Martin Prinz (Paperback)
·
Eyewitness: Rocks & Minerals by R. F. Symes, et al (Hardcover)
Rockhounds has a table at the following Internet address. http://www.rockhounds.com/rockshop/mineral_id/#Sec_IA
Or see the Atlas of Igneous and Metamorphic Rocks, Minerals and Textures:
http://www.geolab.unc.edu/Petunia/IgMetAtlas/mainmenu.html
Culminating Project: Individually or in groups, students find at least 6 rock samples and make a guidebook to go with their collection. For each sample will have its own page and should include the following information:
· Where was the sample found?
· Is it a rock or a mineral?
· If it’s a mineral, what kind of mineral is it?
· If it’s a rock, is it igneous, sedimentary or metamorphic? If possible identify which kind of rock it is.
· List the attributes of the sample.
Additional Activities:
· Go on a field trip to the Natural History Museum
· Hide samples outside, have students locate using compasses, characterize and identify samples, assuming that the rock was naturally occurring there, make a theory about how it got there.