ID help

[arrow86]

I found this in a creek bed where I find a lot of points and pottery. My first thoughts were natural but it's so square and well defined it's got my scratching my head. Again I lean towards natural from a practicality standpoint .... What would the use be? The inside of the square is smoother and has the same feel as a polished stone would have(almost a wax feeling ) Anyways thought I would get some feedback from you guys . Any comments welcome . Thanks

 

[Bass]

Not sure what it's for but I don't think it's natural

 

[creekhunter]

Never seen anything like that, but agree it really doesn't look natural

 

[Indian Steve]

I have seen quartz with square holes where galena crystals popped out.

 

[theviking]

A Pyrite Crystal eroded out, leaving what we see. Or galena crystal , we posted at the same time..