This tube shaped item has a hole clear through.
It is 3/4 inch diameter with a 3/8 inch diameter hole.
It appears to have distictive growth rings.
The item below has a similar texture but has possible growth rings
around it rather than across like the one above. It is 5/8 inches thick
and if complete would have a diameter of approximately 5 inches.
If it weren't for the alternating colored rings I'd say it was pottery.