Geode fossil found Port Charlotte, FL?
Found this in Port Charlotte, FL
I emailed my cousin Ken, he is a gemologist with over 21 years of experience and it looks like a stone he cut will soon be displayed at the Smithsonian in Washington, D.C. Here's what Ken said about my find:
"Although internet rock ID is not always that
accurate, it looks like a calcite or quartz "geode"(s) that's been broken open. Normally, not a big deal, but where you found
it is. Could it be possible it was transported, at one time, by Native Americans or ? to where you found it? I know I have
rock piles on my property now that have rock from various states that are not native to my area. Some day in the future
someone might be building condo's or whatever and find this misc.pile of agates, obsidians, fossils, petrified woods, various
crystals, and more and wonder how on earth these strange rocks got there..
Just a theory."
Check out Ken's website: www.gemsofmine.com
So Ken, I went back to that spot and looked a little closer. I found almost the whole geode! As I mentioned there is a drainage pipe directly under this spot so it has been dug up and perhaps some fill trucked in.But I wouldn't think they would have had to bring any in since so much was moved to form the canal and drainage ditch. And if it was brought in it couldn't have been from very far.
Why would native Americans carry geodes? More research is needed, but I thought you'd like to see these photos.
I've been Googling a bit and found this: www.paleodirect.com/pgset2/cor-043.htm
June 5, 2007 -- The more I read about geodes found in Florida the more I think this may be some kind of fossil. You can see in the photo where I'm holding the pieces in place a clear pentagon in the center. This is repeated on the bottom side. There are creases that run from corner to corner of the 2 pentagons and the area between those creases are kind of balooned out. It seems like it has to have been a living creature at some time to have this symetrical shape. I'm thinking sea urchin, but I'm not very well educated when it comes to prehistoric life. I'm wondering if a good cleaning will expose more detail on the outer surface.
I did learn from the Tampa Bay Rock Club's website that the inside is a drusy formation which means crystaline or sharp as compared to a botryoidal formation which is smooth and grape like.
See: Florida's Agatized Coral By MICHAEL "DUSTY" ANDERSON
In an email on June 11, 2007 Fred Hendershot of the Tampa Bay Mineral and Science Club wrote:
Hi Tim,
Yes, you have a calcite geode formed in a bubble left by something else, but I'm not sure what?? In Fort Drum Florida there is a shell pit that has calcite crystals formed in a cavity left from a dissolved clam shell. The calcium to make the crystals comes from the dissolved shells since the shells are more soluble in water than the calcite crystals that grew out of the solution. In Brooksville Florida we visit a limestone pit where we find sand dollars and Sea urchins, sometimes with small calcite crystals in them, but not as large as your photo. So your geode came from a limestone or shell quarry, but I can't say what formed such a symmetrical hollow for the crystals to grow inside??
The druzy mentioned in Dusty Andersons article at the Tampa web site refers to Tampa Bay Coral which has quartz, silica based, crystals rather than calcite. The quartz crystals are much harder and durable than the calcite. Since coral is also calcium based, I have no clue why Tampa Bay Coral ended up with quartz based crystals, it would have to do with the water chemistry at the time. My guess is that your specimen did not originate in Port Charlotte but was discarded by someone who didn't think it worth saving when it broke into small pieces??
Fred Hendershot
Field Trip Chairman
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