i can tell you right from the get-go, the discussion of impurities found in street meth will far exceed the scope of this thread. there are numerous forensic reports that attempt to identify all the impurities, but with all the possible synthesis variations it will bee next to impossible to outline them all. i will attempt to define some impurities that would cause a different color other than white (and by white i mean clear, just clear isnt a color)
hmmm, where to begin... i guess first we should look at how meth is produced. for the sake of this post, i will keep the discussion limited to the reduction of secondary alcohols (i.e. pseudoephedrine and ephedrine) as this is how 95% of street meth is produced.
keep in mind that many of the statements about a samples quality in relation to color are purely subjective. state of mind and the quality of reduction play a major role in defining a 'good batch', so with that said here we go...
many times, the starting feedstock (pseudoephedrine) is isolated from cold medicines. in many of these medications, there are other ingredients such as foilants, antihistamines, binders and colorings. if the chemist (and i use that term loosely) does a shitty job extracting the pseudo (or worse yet, they GUPchuck.. Ground Up Pill chucking without first extracting) then the end product will bee adulterated with these other excipients. this is the first source of color found in some samples.
the dye on the 240mg brand name pills is a bright blue/green, and many times this dye will find its way into the end product. this meth will actually look blue/green from the start. it doesnt hurt anything per say, but it isnt what i look for in meth. i typically see this with people that utilize the SnB with brand name tombstones. sometimes the dope is good, sometimes ehhh... in this instance the color is neither here nor there when trying to analyse quality prior to ingestion.
next we have the antihistamines. the two most common are chlorpheniramine maleate and triprolidine. both of these are amines and have similar solubility properties as meth, so these will end up in the end product unchanged. their appearance isnt fully seen until the sample is melted and resolidified (cracked back, in tweaker talk). when the adulterated sample is cooled and rextylizes in the pipe, you will see that the xtyl is no longer clear or slightly yellow. instead it has a blue or green transparent tint to the xtyl. the triprolidine will leave a blue tint, thus is is commonly called 'smurf dope'. chlorpheniramine maleate, on the other hand, will behave the same way but yields a green tint and thus the moniker 'leprechaun dope'. had the 'chemist' taken the time to prewash his feedstock in some dry acetone, neither of these antihistamines would bee present.
in addition to the above two, you also have loratadine. loratadine is different in that it can bee reduced, so the end product will contain the reduction product of loratadine as well as pseudoephedrine, called desloratadine. the appearance of desloratadine is not apparent as it creates no color change prior or subsequent to melting/rextylizing.
in either of the three cases, these antihistamines can cause other symptoms that can bee confused with the effects of the meth. lightheadedness and vertigo can bee caused from the high level of antihistamines present. or the low blood pressure or whatever else antihistamines do in large doses, so you must take that into consideration when criticizing the effects of a dose/hit/line or street meth.
now we'll take a look at another source of fuckedupness that doesnt concern the feed stock at all. its that 'pink' dope... now, there are two types of pink dope that i have seen, and neither of them is what i look for in good street meth. the least common reason for the pink hue is a wonderful product called glo-tel. its a benign additive to anhydrous ammonia that binds to water (like your skin and eyes) and leave a nasty pink stain on everything it comes in contact with. its used to discourage people from jacking anny at the farm houses in rural america. i wont touch glo-tel dope... it will stain your veins pink from the inside out, no shit.. google it. you can see the pink in the pics. this is much pinker than the pink achieve by the next example...glotel demo)
the second and most common reason for the pink dope is the over acidification of the freebase. your meth freebase must be converted to a salt before it can xtylize. this is mostly done using hydrochloric acid, by either 'gassing' or 'titration'. either method will produce a pink tinted dope that burns like fuck if you slam it and itches in your throat if you smoke it. it doesnt affect the potency of the dope, just the overall quality. again, if the cook (im not calling them a chemist anymore) knew what the fuck he was doing, he would have properly tested the pH instead of gassing the fuck outta his shit. pink dope can look a shade of red or even brown depending how much the dumb fuck overshot the pH. the residual acid can bee washed away with anhydrous acetone, fyi...
and what else..
people that cook dope with HI made from mbrp that do a shitty job filtering can have little brown or red specs... these dont dissolve in the spoon and they dirty the pipe. yuck...
oh, and another is the blue tint again. many cooks like using camping fuel as the non-polar, and many times this is dyed blue (its a military thing dating back to the korean war, another story) and if the end product isnt washed of the residual traces of this np it will appear greenish/blue, but on the outside of the xtyl, not inside...
one common mistake is using too much lithium or sodium in your birch. this tends to over-reduce the pseudo and makes the end product yellow/clear. this dope usually sucks ass, so i steer clear. this isnt to bee confused with 'lemon-drop' or 'peanut butter' crank... thats a whole 'nother story. one mans lemon-drop is another mans piss-colored crap... i wont get into the sematical debate over what either of those are, because there is nothing solid to discuss.
as a good rule of thumb: 'if it aint white, it aint right!' im talking about street meth you racist fuckers.. ok, fine.. this one works too: 'if it aint clear, its aint good gear!'
just remember the description in the merck and stick to that: 'Methamphetamine is a white, odorless, bitter-tasting crystalline powder' if it smells, isnt white, and isnt entirely bitter.. than something is not right. period.
what else... i cant think of anymore bullshit at the moment, but if i do ill throw it in this thread.
i hope that helps some...