Bay Pirate,
I understand where your coming from but there are no facts to confirm anything. Yes they could be gaming pieces or something of that nature from Natives.
Unless you find a actual site in the vicinity and excavate it that's probably the only way you'll be able to confirm based on the chance you find more like it. Or maybe a local museum?
Nature makes perfect angles all the time. Perfect circles, triangles,hexagons ect..... I've been to spots where these forms are all over the place. But like I said before either way they're cool so if you like em keep em!
I haven't been on Tnet very long but one thing I've noticed is people filling up specific threads with tons of - what is this- Questions Or -is this a Native American Artifact? I personally come to these sites to look at the cool stuff found by fellow enthusiast so if some people come off as rude or snappy they're probably pissed because they just made a cup of coffee and went on the site to see cool finds. Instead they're bombarded with -what is this posts. I don't think anybody was trying to insult your intelligence they are pretty much telling you what they would be telling themselves if they found those rocks. They're just being honest.
