Hello this is one that I have never heard off.

SWIM after his first extraction decided to experiment a bit and add DMT to water. Don't ask me the reason. He found that a small layer on top seemed oily. My guess is that it is probably nafta that is wetted on the DMT and was not dryed properly. However, he swears on his mothers grave that he has dry it properly. So the last thing I can think of is that some solvent remains in the crystal lattice. However, his dmt is white and I feel that is very unprobable. To fix it and hopefully recover the DMT I told him to just let it evaporate to dryness and hopefully collect nice crystals without solvent.

Can somebody confirm what is that film? Why does it form?

Thank you

If you dissolve DMT in pH 3 water and then basify it to pH 11+ then you will also get the same results: Some DMT will form clouds that stick together and slowly sink to the bottom and another part will float to the surface and form a top layer. Well it may not quite look oily, but at least it's material floating on top of a surface.

If you are now concerned that you cant retrieve it easily, then why not just throw Naphtha on it again and extract from this? Then either evaporate the naphtha or do the freeze precipitation.
Evaporating water will always form a rock solid flat layer of stuff that was present in it, making it hard to break it apart from any surface. Also it takes ages for water to fully dry ;/