Wednesday, January 30, 2013

Outdoor Hour - Rocks & Minerals

The weather this month has really not been conducive for getting out and looking at rocks.  We have had snow cover all month and the past week has been especially cold.  (Excuses, excuses!)

That did not mean we could not do some rock study though.  We got out our box of rock and mineral specimens.  Many were from a rock shop in Estes Park, Colorado that we visited several years ago.  I remember we had a great time looking at all the different rocks and choosing ones to take home with us.  This can't compare to digging for rocks yourself, but it does allow you to get a variety of rocks and minerals from around the world.  Thankfully, I had the brainstorm to take pictures of the rocks in the labeled containers in the store.  Our rock box was not at all organized or labeled, so without the pictures, we would have had a pretty hard time identifying them.  (Although, I think it would be a good test to try and identify them using a guide book or website and see how far we could get).  B went ahead and made identification cards for them and put them on display.

The other activity we did was to grow crystals.  We started with Epsom salt crystals.  We have grown Borax crystals in the past, but I liked the results of the Epsom salts better.  They grew more quickly and had a much more delicate look.

In the process of digging out our "rock box", we also found some crystal growing activities that I had probably bought as stocking stuffers, but had never used.  One kit came with some "magic" water and a little cardboard tree.  The tree sucks up the water and the crystals form on the branches.  Not as spectacular as hoped, but it probably has to do with the temperature and humidity level (lack of humidity right now) in our house.

In the box, we also found some Popcorn Rock.  This is a limestone rock that we put in a glass bowl, covered with distilled white vinegar and then waited for the vinegar to evaporate.  Aragonite crystals formed on the surface of the rock.  And here is our vocabulary word for the month: Polymorph.  We learned that Aragonite and Calcite are polymorphic, meaning that they have the same chemical composition (CaCO3 - Calcium Carbonate), but different structure.  (The best example of polymorphs may be graphite and diamonds. Both are made of carbon, but because of the different heat and pressure under which they form, they have different structures and different properties).

There is so much more to do, but we have run out of time this month!  We have just started getting into the Golden Guide to Rocks, Gems and Minerals.  For a little book, it packs a lot of information. We will be doing Earth Science next year, so I am sure we will continue our studies.