Howdy
I'm not a marble collecter (although it does seem interesting) but I found this marble beside my house. It was in an area where the water from a gutter washed away the dirt. The house was built in the 40s. The marble is 5/8ths of an inch. It has a few dings, but no chips. It has what appears to be 2 seams, but they aren't at the poles, I tried to get a pic with both in it, the first pic, but they're just far enough away to prevent both from showing well at the same time.
There is a similar looking one at http://www.marblecollecting.com/marble-reference/online-marble-id-guide/akro-agate-co/ called an Onyx Corkscrew.
Any help with ID and possible value would be appreciated.