CAC transitional slag? If that is such a thing

[Marbleized]

Here's a marble that I just got in a lot.  Basically, this is the marble that caught my eye.  I loved all the drizzly glass and the grayish blue color.  While I was looking at it more closely, I noticed an outline of a circle that I thought might be some kind of pontil, so I'm thinking a slag because of the tail, a transitional because of the pontil like circle, and CAC because it is one of the earlier companies that made slags.  Any confirmations or differing opinions appreciated! The last pic shows the circle.

[Steph]

West Virginia Swirl.  

The circle is some kind of error -- I'm not sure if it's from getting hung up on machinery or if it's lost glass from a later incident. 

[Marbleized]

Or maybe the circle is from a reheat where a glass rod was detached? It certainly does swirl!  Thanks!

[wvrons]

Not a slag. It is a Alley swirl.

[Marbleized]

Thanks for the info. 

[Al Oregon]

And, by the way, it is machine made - no rod attached, etc.

[Marbleized]

Thanks for the info!