FMF - Minerals Forum, discussion and message board

[jmercer]

Hey guys. I've always been interested in rocks/minerals but never pursued it, and know absolutely nothing about them.

My fiance bought this for me in southwestern Kentucky, but I'm unsure of it's actual origin. I'm just curious as to what it is and what these black lines inside of it are.

When I zoomed in the picture was too distorted, but inside it it almost looks like pieces of plant. Some are black and a few are white, they run all along the interior of it.

The size is roughly 8in x 6in x 1/4in and weighs 275 grams.

Any information is extremely appreciated!

[Pete Modreski]

J (Jim maybe?),

It looks like no one has tried to answer your message, so I thought I'd give it a try.

The picture is a little too blurry to tell much for sure (unless it is not as out-of-focus as it looks, if that is just the swirly/fuzzy nature of the pattern in it), but it looks like, as you suggest, a polished slab of agate. It's really not possible to say much more about it; generally, the patterns seen in agate are just from mineral growth--sometimes around inclusions of other minerals, sometimes around "stalactite" forms within the agate--and almost never of any fossils, except in the case of agatized wood, where a trace of the structure of the wood remains. Most of the agate like this that one sees, has probably come from Brazil--irrespective of where it may have been purchased in a shop.

I don't know if I can say anything more!
Sincerely, Pete Modreski, Denver CO