Oh man I got an atypical one. Wicked scary in retrospect.
I got a sample of 2 RC's from some random guy. I don't remember 100%, but one was probably MXE and the one in question here was supposed to be 4FA. I had shot 4FA before and liked to do big ol' 200mg blasts of it. So IIRC one bag was labeled as mxe and the other was blank. I assumed it was the 4F and dumped most of it out in a spoon. I threw the water on, and got it in solution with a bit of difficulty. I rigged up like half and stuck it in my arm.
Halfway down the plunger (I go real slow on big shots, especially vaguely unknown ones), I got slammed by a wave of... something. My skin immediately began to just float/crawl (similar to 2C visuals I've had and other hallucinogen patterning, where the surface swims and swirls) and I had trouble even focusing. Idiotically, I continued to push the plunger and must have finished it. The next thing I remember was being in some crazy hallucinogenic headspace. I was a large neutral entity, although I was still kind of aware of myself - so it was different from DMT/LSD ego loss. In my 4 imaginary/hallucinated 'corners of the world', there were elements sort of... North was firey shit/warm, East was watery/cool etc. I had reached singularity with the elements, and with everybody and everything else that ever existed. We were all connected, but still existed separately enough to define. I zoomed around our connection pathways from element to element.
I started to snap out of it. Things are blurry in memory, but as I came to I realized the directions were the sides of my bed, and the 'elements' were pillows that I must have been grappling with. I was still fucked up and almost snapped into a real bad psychosis as I still had this bizarre feeling of being connected to everything/one and my phone wouldn't work (I was probably too fucked up to use it) and I thought... paranoid thoughts about being watched by this 'everything' I was connected to. I calmed down as the last effects wore off.
The remaining liquid in the spoon had separated and mostly congealed/dried into this horrible, stratified mess of BRIGHT fucking chemical colors. That solution separated into these neon fucking chemically layers, hot pink being the main one, with some yellow and whatnot (no not hallucination, this was just how it reacted with air as it dried I guess). I have no idea what kind of poorly made, horrible chemical that was, but I had been in a trance for almost 18 hours. I asked my mother, and she said that I was just tranced out by the time she saw me the previous evening, and it was now midday of the next day. If that chemical had been something more lethal, I'd be dead. As it is, it was one hell of a fucking experience... if poorly remembered.