I found a geological object (type of stone) which I've been told is a root cast, however it doesn't look anything like the cast of a root. We have searched the net extensively for decent images and can find none. Is there an expert out there anywhere that we could send an image to, who might hazard a guess at this specimen please.

I found a geological object (type of stone) which I've been told is a root cast, however it doesn't look anything like the cast of a root. We have searched the net extensively for decent images and can find none. Is there an expert out there anywhere that we could send an image to, who might hazard a guess at this specimen please.
Lehman - (http://www.gesc.ttu.edu/Fac_pages/Lehman/Lehman%20Rough.htm)

This is the man you need to go to, send him a picture of that thing, and he'll tell you. This man knows more about this stuff than any one man was ever meant to.