Not sure what it's called but thinking fossilized coral

[Nick s.]

Hello I could use some help with finding out what I have. From what I've heard and seen on the internet it's something like agatized fossilized coral. This piece of coral weighs right at 18 lbs with shining crystals throughout. Any input would help greatly thanks 

[FranzBernhard]

Welcome to TFF from Austria!

 

Yes, this seems to be some sort of fossilized corals.

 

I can not say, if it is agatized / silicified or not.

Can it be scratched with a knife blade? Does it fizz with vinegar or diluted hydrochlorid/muriatic acid? This would indicate calcium carbonate as major component instead of quartz / agate.

 

Franz Bernhard

[Nick s.]

Thank you Mr Bernhard and hope all is well in Austria. I had not tried those test on the coral until you mentioned them, i ran the blade across both front and back the knife did leave a small white scratch on the front side of the coral but the front side looks like what they're calling druzy ( wasn't to sure if that was a bad spot to test ) And on the back side it left a very small white scratch as well although much harder to see, I used vinegar for the second part which was %45 bit I diluted with water 50/50 and It had no effect at all on any part accept the stuff that I'm guessing limestone mud or more like almost hardened white clay, when it hit that it sizzled then foamed up like a dog with rabies 

[FranzBernhard]

Interesting results!

The  scratch test is pointing towards a rather soft material, for example something based on calcium carbonate.

The acid test mostly seems to exclude calcium carbonate, except in some spots -?

Would you like to put a drop of vinegar on the scratches you made? What happens there? To you have a magnifying glass?
Franz Bernhard