i dont know anyone that thinks that kief or resin is pure thc. yes we know that it is much higher in thc levels than normal weed. thats it. not even sure about the resin (if your talking about the resin from a plant or scraped from a bowl shyt). and its just a sure way to tell if its decent quality bud or not if it has a shitload of crystals. yes there are strains that dont have many crystals that will knock you on yourass but whats more likely. some weed that looks like it came straight from a brick of weed with no crystals or weed that looks silver haze with all the crystals? u get my point. most likely the weed with crystals.