a combination of 'drying' gassing off of solvent vapor and crystallization.
Crystallization size can remain very tiny, especially in impure mixtures, so you won't see any visible crystals. DMT and NMT also tend to form something of an amorphous solid.
You can get also get a similar effect faster doing manual re-crystallization, scraping the goo around with a spatula or razor on a glass dish, it will eventually harden into a crust or powder. By working the goo around you are making lots of tiny nucleation points for crystal growth.
Expect nothing, Receive everything.
"Experiment and extrapolation is the only means the organic chemists (humans) currrently have - in contrast to "God" (and possibly R. B. Woodward). "
He alone sees truly who sees the Absolute the same in every creature...seeing the same Absolute everywhere, he does not harm himself or others. - The Bhagavad Gita
"The most beautiful thing we can experience, is the mysterious. The source of all true art and science."