I've come across some stuff that was apparently a 50/50 mix of mda and mdma. It was brownish/whitish with some red mixed in. I would describe it to look like cherry cola in powder form lol. It was pretty sweet, I didn't do a ton of it because I had already eaten a bunch of molly but I felt trippier after eating it. It was all powder/shards, I'd assume that the goopy-ness if from moisture getting into the substance. It's pretty hard to melt pure mdma (melting temp is pretty high, the melting temperature of MDA is lower but still pretty high), so most goopy molly is from water/condensation interacting with the substance.