Most of the newer runs have a blue transparent base instead of a transparent clear base and the newer ones aren't nearly as articulated as the first run (more sloppy) Here's a pic of my best first run, the difference between these and the newer runs is obvious. Still a very nice marble, the older Michelangelo's are getting up there in price. Mines 5/8ths, James is nearly an inch accounting for the looser pattern.
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