This is one of my favorite ever vortexes from Mike, both inside and out, and VERY hard to let go of. It is another early masterpiece from Mike, and this one STUNNED us when we first laid eyes on it back in 2004. Mike incorporated a new testing pattern on the inside of the vortex, and then those fumed dots on the backside, WOW! Such beautiful glass, this is an incredibly special marble from Mike, one to be cherished in the best of collections. Signed 'MG 04'.