I picked up half a gram from the guy tonight. It was a bag of powder. Not fluffy like 2c-b, but like tiny rocks, with finer powder around it. I dipped my finger in it and tasted it but it didn't taste like MDMA.
Marquis: very very slow change to black.
Mecke: fast change to blue/black.
Mandelin: very very slow change to black with a vague hint of red.
Simons: fast change to blue.
Robadope: none.
[
colour changes]
It seems to be MDMA, though I'm put off by how slow the reactions were. They were slow enough that I didn't think it was MDMA and left the room, but when I came back it was black. I'm happy enough to buy more and I'll be trying it on Friday.