I'm sorry for making so many threads, but I got a lot of fresh ideas (also I think its clearer for later reference to have many short threads with very on-topic discussion than few long threads where discussion is broad)

What about heating freebase DMT to its melting point such that it becomes a liquid. The liquid may attract itself (cohesion) and impurities (salts with much higher melting point) may drop to the bottom. Upon cooling, one big crystal may form that needs to be broken up (like in Breaking Bad).

Is this realistic and has anyone ever tried this? I definitely wanna give this a try if someone doesn't stop me

Why don't you try it and report your results?

In my experience, the easiest way to get large glassy crystals is to dissolve already-cleaned crystals into a small amount of clean heptane and let it evap off very slowly at room temp (like in your garage).

I will try as soon as my emulsion separates...

Crystals freeze precipitated from naphtha should, when the naphtha has been separated with due care from the basic aqueous phase, contain practically zero in the way of "salts with much higher melting point".

coAsTal's suggestion of slow evaporation will be effective - and there's nothing wrong with satisfying your curiosity with a bit of tinkering and experimentation as well.

I once put spice in a glass jar which had previously contained bho. I had cleaned the jar with isopropyl and it still contained a drop or two. This melted the DMT. Took a couple days and it solidified into one piece shaped like the bottom of the jar.

One more vote for slow evaporation.

I once was doing an extraction at a friend's house and left some naphtha pulls in a Pyrex bowl with a plastic lid. It was a few weeks before I could make a return visit. The naphtha had softened and expanded the lid just enough to allow for very slow evaporation, leaving a radial pattern of 2cm yellow crystals. It looked like an overripe citrus slice.

And the same sentiments as DFZ , I'm not trying to discourage experimentation, just wanted to share.

Thanks for the replies. It seems that slow evap is the "proven" way to get big crystals. I will still experiment with melting when I get the chance.

With melting you could fiddle with the polymorphism - melting at 46°C (assuming it's that form) and holding at just above that temperature, the DMT might crystallise again into a higher-melting polymorphic modification. This would require some accurate heating apparatus, and an argon atmosphere would likely be beneficial too.

There's a scientific paper about DMT polymorphism, if you're interested I'll hunt it down and link/post.

Once while camping in the heat, spice melted and when it got cooler it solidified into a block. Not crystalline, but more like hard peanut butter. It was not fun to work with. I ended up redisolving the leftovers in naphta when I got home and it crystalized in the freezer as usual.