Background
For anyone unfamiliar, Mexican cartels have been heavily cutting the meth they make before smuggling it into the US. This has been happening since about February 2017. Although the identity of the cut has never been confirmed, the most likely contender is n-isopropylbenzylamine hydrochloride, aka n-iso. Not only are the crystals of this shit super huge and super clear, but people have to buy a lot more to get the same effect! Although not everyone has a noticeable reaction from n-iso, the people that do typically experience headaches, lethargy, listlessness, procrastination, and/or confusion. The effects are usually mild, but since there's not much methamphetamine at all in most of this bullshit that's being sold, those effects can add up.
Chemical Properties
The best test for pure methamphetamine is the melting point test. you basically set up a double-boiler type system, with hot oil (mineral oil is best, vegetable oil is okay) in the outer vessel and shards in the inner one. Heat the oil with a thermometer in the shards until they all melt. (Temperature should be 180˚C+ in this state) Then shut off the heat and keep an eye on the temperature. Record the temperature that you first see crystals, then record the temperature when the entire mass has solidified. The closer those temperatures are together, and the closer those temperatures are to 170-175˚C, the purer the methamphetamine is likely to be.
The tweaker version of this is "crackback", where you watch methamphetamine solidify in a pipe. If it solidifies slowly around the edges first, with a molten spot in the middle that gets slushy-looking before solidifying, that means it's cut. If it solidifies in a wave, starting at a few points on the edges and moving inward, then it's pure.
"Crackback" only says anything about purity though, not what substance it is. However, this is still a very good test for purity, and it will continue to apply no matter how many new cuts they come out with. If you know that you have a pure substance, you can then use a standard test like the Marquis test on it, and confirm that not only is it pure, but it's the substance that it was sold as.
Since n-iso and methamphetamine are very similar types of chemicals, most solvents will dissolve both of them or neither of them. So you can't just wash away the n-iso with acetone, like you can with MSM.
Research
I haven't been able to afford to do the research I would like as far as studying what the fuck is in all this crystal clear weak-ass meth that everyone seems to be coming across these days. But, I've had a few people help by giving me information, which I can then use to see the bigger picture.
So how about some visuals? First of all, this stuff looks very fake to me:
https://i.imgur.com/dNpOrVr.jpg
Real methamphetamine is cloudy, not perfectly clear. The brown color is something I haven't seen before though. I suspect that since a lot of home-cooked meth is brown in color, and that's typically a lot purer than what's been coming out of Mexico lately, some people are probably now seeking out the brown stuff specifically. So what do you do when your clear stuff is selling for less than brown stuff? Why, add brown food coloring, of course.
This is just my opinion, and I have no idea if that's what was done here.
A test I came up with for n-iso that proved to be popular, was dissolving it in 90% isopropanol in a concentrated solution, putting some on a flat surface, then examining the patterns of the crystals.
I've described the patterns that n-iso-cut meth forms when evaporated from isopropanol as "bizarre", "dramatic", and "something from a Tim Burton movie". The reason is that methamphetamine forms cocrystals with n-iso, and those cocrystals are a completely different structure from either methamphetamine or n-iso. So you have at least three different types crystal growth going on, and the crystal type will switch up as concentrations change. This gives it strange patterns as crystal type will alternate between multiple different ones as the solvent evaporates.
Here are two photos of heavily-cut methamphetamine crystallization patterns. I do not have any photos of real methamphetamine, because of how ridiculously rare that is these days.
On a flatbed scanner:
https://i.imgur.com/gc4p8oc.jpg
Close-up:
https://i.imgur.com/f6Uv90j.jpg
The biggest difference is that n-iso forms flat, plate-type crystals extremely easily, whereas methamphetamine is actually pretty hard to coax into forming crystals, and they will usually be kind of crusty and hard to grow larger than rice grains without putting a lot of effort into it. One of the easiest visual tests for n-iso is by looking to see if there are a lot of smooth, very flat crystal facets. For instance, in the following image, you can see a large flat facet pretty easily. These types of facets are something you usually only see in real methamphetamine from where it was touching the container.
https://i.imgur.com/e9fUyQh.jpg
Unlike most methamphetamine cuts, there is no way to wash n-iso off. Since this shit is mostly n-iso, you actually have to do it backwards: separate the impurities from your relatively pure n-isopropylbenzylamine, then extract methamphetamine from among those impurities.
The way you can tell the difference when you see crystals form, is that n-iso forms flat, layered crystals under the right conditions. It can also form cocrystals with methamphetamine that look different, but preliminary tests seem to confirm that the flat layered ones are fairly pure n-iso. The following procedure seems to be effective at concentrating methamphetamine from product that's mostly bunk:
Dissolve a large amount of your shit in as little boiling 90% isopropanol as you possibly can. Take it off the heat when there are just a few specks left that are solid. Cover it and put it somewhere to cool, then don't touch it for at least an hour or two. You should come back to find a bunch of flat plate-like crystals at the bottom. My money is on those being n-iso. Pour off the liquid into something else, and allow it to evaporate. If it looks like there's a lot of n-iso contamination with whatever's left, you could try repeating it. All I know for sure is that both methamphetamine and n-iso aren't super soluble in pure isopropanol. But having 10% water in the isopropanol seems to greatly increase its ability to dissolve methamphetamine, but not n-iso. This is all very preliminary, and based on observations of a friend. I can't do more research until I can afford to though. I cannot rule out the prospect that I am totally wrong about something, but initial tests seem to confirm that this procedure can be effective.
Other Cuts
Probably the most common other drug to find in methamphetamine is alpha-pyrrolidinovalerophenone, aka aPVP, aka "flakka". None of the commonly-used drug testing kits do a very good job at distinguishing this stuff from methamphetamine. It's also quite a bit more potent, and quite a bit more paranoia-inducing. It's basically the methamphetamine equivalent of fentanyl. You're less likely to die by overdosing, perhaps, but more likely to die being shot by a cop after attacking him with an icepick. Flakka no es bueno.
Spread Awareness
If your tweaker friend gets all excited that he got a giant clear crystal in his bag, tell him that may as well be actual fucking ice, which would be a lot cheaper if he just got it out of his freezer.
If a darknet dealer is "always heavy" in the feedback, that probably means he can't unload this shit fast enough. If he's selling kilos at a price that works out to about $10 a gram, that because that's how much he paid the cartels for it it and he's looking to get rid of it before more people catch on. If comments praise the size and clarity of the crystals, enough said. Most buyers on the darknet are dealers themselves, and care more about how it looks and how often customers return than they care about quality. There are plenty of darknet dealers who buy the same shit as everyone else and tell you it was made locally, or made by some guy he knows personally. Most of that shit is lies, and those people will say whatever the fuck they think will convince you to buy from them.
Great work my friend. Not a fan of the funk myself but keep spreading awareness.