The wikipedia entry on polymorphism:
http://en.wikipedia.org/wiki/Polymorphism_(materials_science)
From an undisclosed knowledgeable source on polymorphism particular to MXE:
"Given that Methoxetamine has been and continues to be produced presumably in Megagram (1,000 Kilogram units) quantities by different facilities around the world over the past two years it does not seem surprising that several polymorphs of Methoxetamine would have been achieved by various production facilities during this time. What is somewhat striking is that, as far as can be ascertained, it has become increasingly apparent that different polymorphs of Methoxetamine may produce certain effects so distinctive from one another that a person experienced with one polymorph of MXE may incorrectly conclude that a different polymorph of MXE is not even Methoxetamine but is some other compound (such as 4-Meo-PCP or N-Ethyl-Ketamine) that has been incorrectly or fraudulently traded as Methoxetamine)."
Lol, I've had dark, strange thoughts creep up on me when I started dosing too much and repeatedly. Sometimes I felt like I was going to lose my wits and really had to make an effort to center myself haha. These weren't even hole sized doses lol. It can be a strange compound that is for sure.
But blacking out from a lowish dose just does not sound right my friend.