Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: JayDay on 13/09/2011 12:51:27

Title: An odd rock I've had for 30 years
Post by: JayDay on 13/09/2011 12:51:27

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.

Title: An odd rock I've had for 30 years
Post by: RD on 13/09/2011 14:38:36

Maybe chalcedony ...

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Title: An odd rock I've had for 30 years
Post by: JimBob on 15/09/2011 03:21:41

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.

Title: An odd rock I've had for 30 years
Post by: JayDay on 15/09/2011 11:37:17

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

Title: An odd rock I've had for 30 years
Post by: Bass on 16/09/2011 03:40:08

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?

Title: An odd rock I've had for 30 years
Post by: JayDay on 16/09/2011 08:07:47

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