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Geology/Strange rock. (Magnetic)


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My son and I found this my a stream in our local area in east ky. I've never seen anything like it. Resently discovered it was magnetic. Can you tell me what it is?

Hi Richard,
VERY interesting rock you have there.  Looks like a piece of vesicular lava, but for the fact that it's magnetic. That doesn't happen to lava.

There is a type of material called metallic slag that is a waste product from a smelting process.  It can have magnetic properties, and usually has many vesicles (holes left over after gas escaped when the piece hardened) like your specimen, but it is usually silvery.  Your specimen doesn't appear to be metallic/silvery from your pictures.

The next most likely candidate is a meteorite.  Now that would be cool!  Does it seem much heavier than it should?  We all have an innate idea of how "heavy" something should be just because we handle stuff every day.  You have a "feeling" on how heavy your rock should be; does it feel suspiciously heavier than it should?  Metallic meteorites feel much heavier than they look.  Many meteorites can be vesicular but metallic meteorites generally not so much.  They DO have regmaglypts.  These are shallow pits in the surface of the rock that look much like thumbprints.  Yours doesn't have classic structures but yours does look something like this one;

Most iron meteorites exhibit metallic crystals that look like shiny flakes on a polished surface.  You might want to grind a small area on your specimen to see if you can spot them.  Here's a site that has some good information on identifying a meteorite;

Barring other odd occurrences I am inclined to ID your rock as an iron meteorite.  For a more definitive answer you should take it to a local university.  The Geology department should be able to help you.

Hope this helps.


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C. Robert Reszka, Jr.


I can answer any general geology question (rocks, minerals, stratigraphy, geomorphology etc.). My expertise is in the geology of the Michigan Basin, PreCambrian, Paleozoic and Recent. I can answer questions concerning mining and petroleum exploration and production and the laws concerning those activities. I can also answer questions concerning stratigraphy of the Michigan Basin. I will also answer questions about mineral and rock collecting in the Basin. I won`t be able to answer many specific questions on hydrology, geophysics or geochemistry. I may be able to answer very general questions in those venues.


I have been working for the State of Michigan for 36 years as a Geologist and a Resource Analyst. I have experience with Subsurface Geology and Petroleum Geology, mining in Michigan, and Sand Dune Mining and Protection issues.

Michigan Basin Geological Society

Decade of North American Geology.
Bedrock Geology of Michigan

BS Wayne State University

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