image links to larger version.
The vial on the right contains almost pure white snow with a hint of yellow. After reusing the same naphtha and applying some heat for subsequent pulls SWIM obtained the waxier yellow crystals on the left. The crystals were freeze precipitated with a single freezer-countertop-freezer cycle then dried using a furnace vent (hot dry air). SWIM noticed some oily liquid which did not evaporate and may be partly responsible for the yellow color.
SWIM is planning to do a recrystallization by mixing all the spice together with just enough clean, heated naphtha to dissolve everything, then separating the naphtha layer from any impurity layer and freeze-cycling to form thicker crystals. Will the recrystallization help to remove the yellow impurities, or will it just spread them to all the crystals? Is it possible that SWIM applied too much heat & air, forming some N-Oxide which would be inseparable from pure N,N?
