I've heard there are some real huge ones out there, but most were kept under 2.5" due to deformation during manufacture, is that still the consensus? (I imagine the glassworker could pretty much attempt any size they wanted).
There were probably some factors like packaging, limited market, and raw materials (1 huge marble vs. ~40 small marbles) etc.
Mostly curious how they would have been marketed, or if they were simply one-offs. Largest I have are a couple around 2-3/8"