Pretty sure good street H is more than 20% .. 40 +%. Would be considered good. As for McNutter and his 2% bags that would be straight rip off to me . Seems I must of got some of him a couple of weeks ago, the bastard.You'll never get it "pure", not no.3 anyway, as it would kill ya. It isn't just cut for greed, it is cut to a point at which it delivers a high and is smokeable (hence caffeine - burns at the right temperature for the gear to be smokable). I might not have my numbers right but 17-19% is considered to be high purity and this isn't just due to it being bashed, much of the packaged heroin contains by-products of the processing process (have a look at the minor components on wedinos samples - you'll see stuff that is just a by-product of the synthesis). By the time it has been bashed down the line from the docks down to Johnny McArdnut on the estate and his band of runners, you will find a purity of 2% in some places. I'm not sure what's considered "good" now - probably up to about 10% actual heroin, plus by-products via the process of synthesis and then cuts added for bulk/greed
But yeah, as far as I know, good quality heroin will have a purity of up to 20% and will contain by products from the processing of opium into heroin which make up much of the bulk, and then cuts are added. Heroin of a purity that is too high would kill too many people. And also, you can't tell visibly what "good" heroin looks like as decent gear could look exactly like a shitty bag of 2% purity.
Best gear I ever had was dark brown, almost shit like consistently (as in actual shit) and I thought I was ripped off until I smoked it and it was amazing. I'm not sure what it was or why it had that consistency. It could've been opium I suppose. That's what it looked like and it had that beautiful heroin smell. Never saw it again and only scored through this guy to get crack for my friend's friend who was up and the guy even apologised when I said this looks like shit. Normally you'd get usual no3 heroin, golden brown (hence the song) in this area. There is no way to test the purity - once you've smoked a bit you should get an idea of whether it is decent enough by your standards.
Had to pay 1993 prices to get good stuff the other day.