Thanks again, @SafeLeaf.ca !
Please let me explain my hypothesis (POST 337) again, @Zack_illuminated & @standardoil . Also see post numbers 243, 267-269, 289, and 312 (pretty much EVERY post in this thread from @SafeLeaf.ca) as background on the subject. As you can guess, the idea is the THCa forming a complex “salt” with a secondary or tertiary organic amine compound, such as diethanolamine (DEA), diethylenetriamine (DETA), or methyldiethanolamine (MDEA).
NOTE: This is NOT a typical ionic or covalent bond, but what is known as a complex coordination or dative bond… and it is literally as simple as one of each of the WHOLE THCa & organo-amine molecules sticking together at the COOH-NR site (R = 2-3 organic groups).
This new THCa*Organo-amine compound (I’ll call it “salt” for brevity) is fairly—but not entirely—INsoluble in the butane/BHO solution, and it crystallizes rather perfectly in distinctly faceted ‘bars’ or prisms.
Now then…
A. With HIGH concentrations of amine in the BHO solution, the formed “salt” undergoes rapid nucleation with very little growth and subsequent precipitation at high speed… AKA: fast-crash
B. With LOW concentrations of amine in the BHO solution, the “salt” forms at a pace slow enough for it to join other “salt” molecules in a lattice, growing lovely prismatic crystals.
HOWEVER, the sum attractive force between the THCa and the organic amine is only slightly stronger than the sum repulsive force, making the “salt” bond rather tenuous. This bond is delicate enough to be broken by the energy of butane molecules “bumping into it.” Therefore, when the “salt” forms a bulk solid (precipitates as nucleates & crystals), it essentially stops moving relative to the surrounding liquid phase molecules, and the butane easily redissolves the smaller organo-amine moiety!
This leaves tiny, organic-amine-sized HOLES in the lattice of [The THCa solid formerly known as “Salt”]… AKA: medusa petrified stone
Thus, the bizarre looking medusa stones and fast crash material are still just normal THCa, for all intents and purposes (vaping, recrystallizing, etc.), as we have found evident by numerous means.
The “salt” formation is almost catalytic in nature; the organo-amine being a ‘catalyst’ for crystallization of THCa, in that the amine is regenerated after product formation.
This explains why the fast-crash and/or medusoid crystal problems continue throughout multiple batches run with the same butane.
It could also explain why the impurity remains undetected: It only needs to be present in teeny tiny trace quantities to have a significant (and lingering) effect on our processes!