One of my marbles - clear with a rainbow spiral inside. I forget who made it, but it's initialed by the maker - I bought it at a marble show several years back.
Update...I tracked down the maker with the help of major marble purveyor I've dealt with before. The artist's name is Eddie Seese (the miniscule initials he etched at one end of the color spiral read "FES". Look for other works of his - there's some good stuff.
The dealer who helped me on this has a URL of www.marblebert.com and an eBay ID of Marblebert.
I hope this isn't all too commercial, but this marble image is consistently one of the most popular of my images, so I figured there might be at least some people who would want to know its source.