Need help identifying a whatsit.

[Mud Magnet]

Found this in a ditch alongside a highway in Montana when I was a kid in the 70's. Diameter = 1 5/8" circumference = 5 1/2" and Heigth = 2". It weighs 131.9 grams (4.65 oz.) and leaves a red streak on a porcelian tile. There is not reaction when it is passed under the coil of a metal detector so I am assuming it is some kind of rock.

Any help you can give in identification is greatly appreciated as it has been confounding me for 30 plus years now.

[baywalker]

Bakelite ?

Jonnie

[Breezie]

I'm wondering if it could be Hematite, which is blackish in color, yet leave a red-brownish streak on unglazed tile. Does it attract a magnet? Interesting find, Breezie

[Montana Jim]

I'm wondering if it could be Hematite, which is blackish in color, yet leave a red-brownish streak on unglazed tile. Does it attract a magnet? Interesting find, Breezie

I thought that too, but couldn't find a similar picture. Is it too smooth to be a geode?

[Breezie]

Maybe it has been carved. Breezie

[Mud Magnet]

Sorry forgot to add that it is not magnetic to original post. Hadn't thought of hematite, thanks will check into it. Also it seems fairly dense and heavy for its size.

[yaxthri]

Looks like a worn "Moqui marble" hematite concretion, I agree with Breezie.

http://en.wikipedia.org/wiki/File:MoquiMarble1.jpg

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

[Mud Magnet]

Thanks guys, I think hematite is a match.