Although MDMA has "methamphetamine" in its name, that doesnt mean it has anything to do with methamphetamine, in the same way that the "DMT" in psilocybin is not actually dmt somehow secretely 'locked away'. It's the whole structure that counts. MDMA's structure resembles a combination of amphetamine and mescaline. The difference between methamphetamine and amphetamine is like the difference between H2O and N3H2O. As soon as you change *anything* in the molecular structure, everything can change.
you can look at the consistency and tell. once you have seen good molly shards you will know whats cut. the cut shit looks kind of dull, and you can taste the baking soda or whatever they cut with. the real shit sparkles like diamonds and is fluffy and you can taste god awful bitterness and nothing else.