What test did your friend use?
Using the Marquis test kit an MDMA sample is supposed to turn black or at least deep purple/blue in under 3 seconds, methamphetamine is supposed to show up as quite a different colour than MDMA - meth should be like an orange or brown colour. I'm not sure what happens when you have a mix of both meth and MDMA though. And of course in order to be 100% certain you would need to send it to a lab for gas chromatography mass spectrometry testing.
I have heard of urine drug tests not being able to differentiate between methamphetamine and some other drugs, but I'm not sure about substance reagent test kits. Test kits aren't perfect and they can sometimes give false positives or inconclusive results, especially if there is a lot of cut in the substance (especially the less specific tests like Simon), but I've never
heard of there being a widespread problem with MDMA specifically falsely testing positive for methamphetamine on reagent tests. I have heard of mephedrone and other drugs testing positive for methamphetamine on a methamphetamine reagent test like the Simon test. Is that the one your friend used?
Is there a reason you think it could be MDMA? Like was it sold to you as MDMA or something? Or were you hoping it was MDMA and not meth or vice versa?
Here is a site with an MDMA identification guide, but bear in mind that just from looking at a substance you can't be sure, but it might possibly help you rule it in or out.
http://www.bunkpolice.org/mdma-identification-guide/
Here is the EZ Test kit for MDMA (and other substances):
http://eztest.com/ecstasy/
spongle1987 said:
I was under the impression that mdma also came up false positive or even positive for meth.
I don't quite understand what you mean by that. If a substance was
pure MDMA and it tested "positive" for methamphetamine then it would always be a
false positive. That's what false positive means, when a sample gets a positive test result for a substance that is not actually in the sample. If the sample did contain meth but also had other substances in it, then it wouldn't be a
false positive, it would simply be detecting the presence of meth in the sample.