Oh, this reminded me:
The way Sephiroth speaks of it, I thought that materia has to be artificially produced. Or artificially crystallized, or whatever. I remember reading that natural crystallization takes a long ass time, like hundreds of years. I don't remember where, so someone please confirm or correct me, but I'm fairly sure I'm not making this up.
This would explain the size/color differences then, especially the distinctive look of BM and WM from standard, mass-produced materia. Y/N?
Seeing as the natural materia was big, shapeless, and average colored, I don't think natural is the common denominator. And since materia doesn't seem to grow like bulbs on xmas trees, it's entirely possible that someone in the distant past took and refined the black and white materia into the shapes and sizes they have now. As far as their color goes... well, there's both artificial and natural green materia, so I think the color of the BM/WM has to do with their unique powers rather than how they were created.
And, as far as size goes... maybe it's just the perspective of the angle of the youtube videos and the images scattered around, but the black materia in dissidia looks bigger than it did in ff7. A lot bigger. Maybe someone can get a really good closeup shot of the black materia right over Seph's hand? It seems much larger than an orange to me.
I don't know. It's possible that the sizes of the WM/BM were changed, and symbolically, if Sephiroth is bumming around with the BM, it makes sense for Cloud to have the white. But then, on the other hand, isn't the WM normally supposed to be... white? Unless it's permanently stuck on green from answering Aerith's prayer, which would be dumb. And, does all this Dissidia shit happen before or after the prayer, or is time meaningless in this context?