[JayDay (OP)]

I've had this rock since I was a kid and was wondering what it is exactly. It looks like a quartz on the smooth side but with some smooth edges as if formed in a liquid state and the outside is very rough with an orange color.  It's pretty dense and heavy for it's size. Any clues? Thanks in advance.

[RD]

Maybe chalcedony ...

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http://www.mindat.org/photo-364250.html


http://en.wikipedia.org/wiki/Geode


 

[JimBob]

agate

it is a banded chert deposited in layers, usually in warmer water than most cherts. The ability to differentiate from chalcedony is almost impossible without x-ray detraction or similar methods. Thus, in the field the terms can be used interchangeably unless you have a 4 sided piece of chert.

[JayDay (OP)]

Thanks for the replies. Is it common to find a rock like this in North Texas?

[Bass]

obviously some sort of cryptocrystalline quartz (chalcedony, chert, agate, jasper) and the rings indicate it grew in some sort of void.  What type of rock is exposed in the area where you found this?

[JayDay (OP)]

I really don't remember where I even found this rock. I think it was in a creek near my house though. It was 30 years ago. lol