Breaking Open a Geode

I have a geode-themed entry this time!  (One of my favorites!)  Specifically, opening geodes.  The trick is not to shatter it and to get as clean a cut as possible.  To show you an example, I bought a break-your-own geode and took some photos as I broke it open.

The first images are me (and my funny-looking safety goggles!) and my dad, TRYING to get the geode open with the Dremel.  Most common geodes are about a 7 on Moh's hardness scale, like quartz, agate and amethyst.  But it matters even more how dense it is, because it is really hard to open a geode of solid quartz with a thin, metal blade.  Since diamond is a 10 on the hardness scale, people use diamond-edged cutters to slice really hard materials, like blocks of steel. 

We couldn't cut through the geode with the Dremel, so we scored it as much as we could with the Dremel, hoping it would be enough.  Then, we took a risk:  "the hammer job!"  We hacked away with our hammer.  The first couple whacks didn't even leave an impression.  I could have thrown it at the ground all day, and it wouldn't have done anything.  But finally, we got it open, and it was a fairly clean cut all the way through.

When I looked inside, I realized it had been worth the trouble - a milky, blue agate crystal, but nothing else.  Just solid crystal.  I was pleased.

Not all geodes are that hard to open; I just decided to get a really heavy one. Try to get a geode that's a little heavy for it's size, but not too heavy.  If you want a nice geode that you'll be satisfied with, I recommend an average weight geode, so it isn't pitiful, with three microscopic crystals inside (those do exist, by the way!).  Also, don't get one that's very heavy, or it will take hours to open, and you risk shattering it.

There are two ways that geodes are formed: volcanic and mineral-formed.  The volcanic is made up of igneous rock that formed and air pocket before it solidified, and crystals grew inside of it.  The mineral-formed geodes are normally quartz and agate - also created in air pockets - but with the help of water.  Air pockets are first formed by the water flowing through the ground through erosion.  An empty, hollow space is made.  Over time, minerals build up from the water flowing as they are filted by the rock around the air pocket.  They build up inside and form crystals.  I haven't learned yet how to tell which was a geode has been formed by just looking at it.  I do know that it takes a much longer time to make large crystals.

Below is an image of some other geodes in my collection.



Clockwise from Top Left: Quartz, Calcite, Amethyst, Thunder Egg



Trammel Fossil Park

This is Josh, and I'm back for my second blog update.  Sorry that there was no new stuff on my blog through the summer.  Now that the school year is up and going, I will try to make an article every other week.  This entry will be talking about fossils.

Ohio's state fossil is the trilobite.  Ethan and I found one at Trammel Fossil Park, in Sharonville.  It wasn't the highest quality trilobite, like something you'd see on EBay for $1,000, but it was a suitable addition to my collection.  I picked and chiseled it out...and then it shattered!  So, I had to get all the bits of the broken trilobite and put it in a bag. 

Look at the photo on the right of the screen - the largest pieces in the picture are the broken trilobite.  The other smaller, stick-like things in the picture are crinoids or parts of other sea plants.

When a plant or animal dies, if they are to become a fossil, they get buried by sediment.  The imprint made by that dead plant or animal remains - that's the fossil.  The type of rock that the fossil shapes is going to be the same rock that you find your fossil in.  For example, the grey sticks in the left photo were imprinted in limestone and the dull, brown sticks were imprinted in shale.  The branched sticks in the separate pile are both limestone and shale.

I also found little, tiny brachiopods (shell fossils).  They are quite common, but it's a big pain finding one that isn't covered by rock.  Then again, I found nearly 100 of them!  It took a long time.  I put them all into a glass jar (see picture - on the right).

The next rock (on the left) is absolutely worthless, but it is a cool example of the sediment layering at Trammel Fossil Park.  The thin, brown layer on top is shale; the bottom, thicker layer is limestone.  These are the same rocks that appeared on the crinoid sticks in the other photo.

My last rock is also a fossil, but I didn't find it at the fossil park.  I did find it in Sharonville, though, on another day.  It wasn't very interesting at all when I found it.  When you put a fossil into a mild acid (such as white vinegar), it dissolves some of the surrounding sediment and preserves the fossil.  That's what I did with this rock, and it makes the fossil stand out a lot more (picture below).

Fluffy Tales! by Ethan

We have a neighborhood squirrel that we named “Fluffy,” and his favorite spot to sit is on our suet cage.  I have no idea about how a 1-foot squirrel can get onto a 15-foot suet cage! Somehow he does it by jumping up 6 feet onto our deck rail, another 5 feet to our windowsill, and then 4 feet more to the suet cage.

  One day, I was practicing a Gershwin song (“I’ve Got Rhythm”) on the piano, when I noticed that Fluffy came scurrying up to the suet.  I thought that he was just getting a snack, but when the song was over, Fluffy went away. The next day, the same thing happened again – just as I started playing, there was Fluffy on the suet cage. Then the day after that, Fluffy was on the suet waiting for me! (He knew that Gershwin was coming up!)

 I wanted to see if Fluffy would stay for a different song, so I decided that I’d play “Minuet in G” (by Bach).  Then, in the middle of the song, Fluffy jumped 15 feet down, flailing, right off of the suet cage!  I got up to see if he was OK, but Fluffy wasn’t there!  So, I decided to go back to the Gershwin tune again.  As soon as I hit the first measure, Fluffy came straight back! 

I wondered about this for a while.  I tried it lots of times, and I always saw the same thing happen.  At last, I came to a very strange conclusion: This squirrel somehow loves Gershwin!

Josh's Rocks - Part 1

Hello, I’m Josh and I am starting a rock and mineral collection.  I’ll keep the blog updated every 4^th week or so on how I’m doing.  I don’t have much to write about this week, since I don’t know much about my rocks yet.  The state I live in is a great source for fossils but not really for minerals.  So, sooner or later, I hope to go on trips further away.  I will also learn about our local rocks and fossils.  Here are a few specimens that I own right now.  Some of them I have found, and others I have purchased.

(Top Left: Quartz formation;  Top Right: Quartz and Calcite Geode; Bottom Left: Gypsum)