oh yeah, also, btw

best way to grow pure crystals of any freebase chemical is to extract into near boiling solvent, dry it with a drying agent like magnesium sulphate or sodium sulphate (MgSO4 baked in the oven is the cheap and best, grind it finely, only a small amount is required, it's just the tiny bit at the bottom of the jar it needs to pull out of the mix)

and then once your warm solvent is dry, ideally, heat it again to near boiling, and put it into a vacuum flask or similar highly insulated container, and then put that inside the freezer, preferably sitting on some spongy material that will stop it catching the vibrations from the compressor

that will get you big gnarly chunky crystals, and after you pour off the solvent, after a few days to a week, the purity is extremely high and it only takes minutes for most of the solvent to be gone, an hour to be sure

this is standard practise in organic chemistry laboratories