This stone was found in a river located in middle Tennessee. We are stumped as to what this may be. Any insight would be much appreciated.
Sorry, had a problem loading the picture. Here it is.
It definitely looks like something waterworn. Do you know its hardness?
Honestly I'm rather uneducated on geology in general. That being said I have no idea how to gauge such a thing as it's hardness. It's definitely very solid. It doesn't crumble at all and I haven't tried to chip it or anything.
Read this article here about hardness - you may find this helpful:
Also see if you can determine the streak:
Well based on that method it's hardness is higher than 6.5. Systematically tried the penny, then knife, then the steel file. The penny left itself on the stone as did the knife. The file served to polish it a bit (that's the best description I have for it). I don't have any ceramic tile but according to the links provided it won't matter if it's hardness is higher than 6.5.
Thats pretty hard. My guess is that its probably a quartz or feldspar concretion. Although the only way to definitively determine that would be to see it and do some more tests.
Alright. Thank you for the insight. I think I may find a local geology group or mineral type shop and have it analyzed.