I followed the Tao of Rue extraction, and in the final drying out of the freebase material, there were small chunks of semi-clear crystalline structure. There was not much at all relative to the total amount (pretty much what is pictured is the extent, vs. ~17g of tan freebase). I did initial basings with lye, and for the final basing used sodium carbonate.
Have sampled the tan material and it seems to be of good purity, does seem to melt and not ignite, but can smolder.
Does anyone have any idea why there were small bits like this or what they are? Hopefully they do not indicate widespread impurity