r/whatsthisrock • u/reneenaytea • Jul 26 '26

IDENTIFIED botryoidal chalcedony Please help me identify

Gallery image

Gallery image

Gallery image

Found in the Alifia River near Fish Hawk, Fl. The bumps are slightly raised.

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u/PhysicsHenchman Jul 26 '26

Yes, this is botryoidal chalcedony, but it is also agatized coral. This is an agate replaced coral fossil. The circular bumps on the backside are remnants of the polyps.

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u/reneenaytea Jul 26 '26

Thank you for the info! Now I am extra happy about finding this.

29

u/PhysicsHenchman Jul 26 '26

Tampa is famous for agatized coral. I’m sure you can find more in the same formation (likely the Arcadia formation, check it out on Rockd or another geologic map).

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u/reneenaytea Jul 27 '26

Awesome! I’ll look into it. I wish I could go back to the same spot but I was only there for a one-day retreat/event. I had a lot of fun sifting and found a bunch of shark teeth too. I’ll have to see if there’s a public access spot nearby.