Wednesday, July 25, 2012

4-H Cloverbuds: Rock and Minerals

Our latest topic in Cloverbuds was Rocks and Minerals.  This is also our current science topic at home (even though I intended to be finished with it a long time ago).  I guess it works out okay by doing it together since this way we had a cool field trip too.

We did the library meeting portion of our study first.   We started by discussing the difference between a rock and a mineral (the lab we did at home for this can be seen here).   I used our REAL Science Odyssey as a basis for the study.

We discussed some of the tools geologists will use to identify minerals.   We had a Rocks & Minerals field guide (I’ve since purchased the Audubon Field Guide), a magnet, magnifying glasses, streak plates, and various tools to determine hardness (penny, nails, steel file, sandpaper and glass plates).  I also had small bottles of vinegar to demonstrate how some minerals will react with acids.  We never did get to that test or the demonstration of how pumice is the only rock that floats, since at this particularly meeting we had mostly the younger members of the group and they do not have an extensive attention span.


I put a chart of the Moh’s Hardness Scale on the board showing where the various tools we would be using fell.   I meant to have this typed up all nice and neat but I ended up running out of time setting things up that morning.


I put up another chart that we filled in as we went through each test.   


In addition to our RSO Rock & Mineral Test Kit, I had an extensive collection of other rocks and minerals that the kids collected when we went to Crystal Caves or from Steph’s collection.


We started by using our magnifying glasses to look at the Appearance of each mineral.  Appearance covered all the characteristics you could determine by looking at the minerals – cleavage, luster, color, etc.

We then rubbed each mineral against the streak plate to determine the streak color.  The kids thought it was pretty neat the way some of the minerals had streak that was different than their visible color.


Our last test was hardness.  We started with the softest and worked our way up to the hardest.   The first test was to see if we could scratch any of our minerals with a fingernail.   We then used a copper penny (must be an older penny to make sure it is copper), a nail, a glass plate, a steel file, and our streak plates.   Each test gave us a range for the mineral.  For example, for something that couldn’t be scratched by a fingernail but could scratch the penny, we knew it had a hardness between 2.2 and 3.2.   After testing each mineral, we attempted to make a guess as to what some of them might be. 


We may redo the testing at home since we only went through four of the minerals and some of the testing was rushed.

We then discussed how it was important to be able to identify minerals since different minerals have different uses.   Silicon is used in computers, feldspar is used to make pottery, apatite is used for fertilizer, and of course, pretty rocks and minerals are used to make jewelry.  I bought some of Steph’s jewelry with me as samples, including some turquoise, tigers eye (a form of quartz), malachite, hematite, agate, and amethyst.   After the kids made their own jewelry with beads.



For our field trip we went to the Franklin Mineral Museum in Franklin New Jersey. 


The tour began in the native rock room.  These were all specimens that were found in the local area of Ogdensburg – Franklin.  The kids all drifted right over to the big hunks of Magnetite with some handy magnets to demonstrate how magnetite is the most magnetic of the naturally occurring minerals.   There were many other minerals to see, as well as old miners helmets and tools.




We saw fossils and petrified wood.


A replica of the mine where our guide showed the various tools that were used, and the mine office….IMG_0347 IMG_0350  IMG_0354 IMG_0355

and demonstrated the bell system that was used to tell the lift operator where miners needed to be picked up.

IMG_0359We went through the fluorescence room where rocks were shown under UV lights to demonstrate the many colors the minerals displayed.  The guide had the kids watch closely to see that some minerals continued to glow even when the UV light was turned off, which displayed phosphorescence. 

One room was a beautiful display of various rocks and minerals that were someone’s personal collection before they were donated to the museum.  Georgie liked the sulfur containing rocks for their bright yellow color….


a big hunk of pyrite or “fool’s gold”….


a pretty piece of iridescent limonite…


and a hunk of mesolite that the guide told us about touching accidently.  It’s not nearly as soft as it looks and in fact those little fibers will actually pierce skin.

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After the museum tour, we made our way down to the dumpsite to collect our own rocks.  It was over 90 degrees and sunny so we didn’t spend a lot of time searching but the kids did have fun clambering around the dumpsite.   We may have to make another trip there in the fall when it’s cooler.   Each kid was able to collect a baggie of rocks and there was a shed available with UV light boxes where they could check their specimens for fluorescence.  Both Georgie and Vicki had quite a few specimens that showed a lot of color under the lights.


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We finished up with a trip to the gift shop and some yummy rock candy.


Next month we are going to do some Sharpie tie-dye and make lanyards.

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