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Post by Sea Faring Wang Dang on Feb 21, 2009 1:23:46 GMT -5
Here a couple of pieces of conquina that picked up here Jax, FL along the St Johns River Banks. This stuff is getting harder & harder to find. I have found fossils in a couple of the pieces in the past when I use to cut them. I can spend an hour just looking at all the little stuff in the rocks.
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Post by frane on Feb 21, 2009 10:08:46 GMT -5
What is Conquina exactly? Is it a sandstone with fossils captured in it? It looks like you could have some stuff in that one in the bottom picture. Really neat looking! Fran
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Post by connrock on Feb 21, 2009 11:16:12 GMT -5
My sister goes somewhere on the fla panhandle to spend the winter and she has seen tons of that stuff. She brought some back here to CT for my mineral/fossil collection and it's pretty neat stuff.
connrock
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49er
freely admits to licking rocks
Member since February 2008
Posts: 753
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Post by 49er on Feb 22, 2009 0:15:55 GMT -5
Interesting conglomerate of shells and smaller stones.
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Post by Sea Faring Wang Dang on Feb 22, 2009 11:52:35 GMT -5
Conquina is a sedimentary limestone that has shells, coral & small pebbles bound together by calcite. It also has a high phosphate content. You can find shells, coral, sehorses, crabs & many other old neat stuff in conquina. The Spanish used for a building material. There are many structure in my area that are still standing that was build hundreds of years ago from conquina. Two of the most famous ones are the Castillo de San Carlos & Fort Mantanzas in St Johns county, FL around St Augustine. I've also heard of conquina being used as fertilizer due to its phosphate content. The State of Florida is trying to make it illegal to collect or mine conquina. I find it on the banks of the St johns River while looking for drift wood & all types of flotsom & jetsom. Castillo de San Marcos was biult using conquina Fort Mantanzas Conquina on the North Eastern Coast of Florida - Casey
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Post by Sea Faring Wang Dang on Feb 22, 2009 12:00:39 GMT -5
Guys, I just realized that I have mispelled "Conquina", its actually Coquina. Brain Fart, sorry.
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Post by frane on Feb 22, 2009 23:02:48 GMT -5
Neat pictures and thanks for the explanation! Fran
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Post by sitnwrap on Feb 22, 2009 23:08:18 GMT -5
That is really neat. You said you can look at it for hours, do you have a jewelers loupe? That rock would be a blast to look at through a loupe.
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Post by Hard Rock Cafe on Feb 23, 2009 13:14:22 GMT -5
Thanks for the correction, Casey! Saves me the trouble of looking it up! LOL I thought it was coquina, but wasn't certain. We stay in Hollywood every summer and usually find some on the beach or in the water. Met a local one year who was picking up all he could find for a garden project. If I remember correctly, it's found only in Florida. I don't think it will take a polish, though! Chuck
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Post by Sea Faring Wang Dang on Feb 24, 2009 0:03:49 GMT -5
I do check it out with a 10X & 20 X loupe and it real intresting stuff. I do believe it's only found in Florida & couple Carabean Ilses. Yea, tumbling would leave you with mud & shell but it would fossilized shell, I think. Any way I always look at ever piece I find then it end s up either in my yard or in my collection. There is a pink variety that is awsome. It is usually found in shallow waters around sea schoals.
Casey
Fort Mantanzas was abondon until a couple of years ago. I use to hang out there and drink beer with my friends a couple of years ago. Now you have to pay for a ferry and a couple of bucks to see it. Darn!!
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Tigger
freely admits to licking rocks
The Wonderful Thing About Tiggers is I'm the Only One!
Member since January 2008
Posts: 896
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Post by Tigger on Feb 24, 2009 11:53:44 GMT -5
Coquina rock is also used by FDOT as a stabilizer in road foundations. I have performed many tests on coquina rock and limestone working for a geotechnical lab. There are many quarrys around that supply coquina for the DOT. It will not polish or shine, just contains a few fossils here and there. Many forts built back in the day were built using coquina, in St Pete, Palm Beach, St Augustine,Ft Myers, all along the coasts of Florida. I think I would call it Floridas' Rock cause that's all there is!! LOL There is other types of rock in the northern area of Fl. but most is on private property. Sometimes you can find stuff in the road cuts, if they will let you look.
Tigger
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Post by Sea Faring Wang Dang on Feb 25, 2009 18:24:41 GMT -5
I did not know that coquina was mined in Florida. You learn something every day. I have seen roads & sidewalks with shells in the asphalt/concrete & never even though twice that the DOT was using coquina. As far as rocks go you are pretty much right, slim pickings here in FL.
Casey
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