Drug info - Black Tar Opium?

[mouthwater]

SWIM lives in one of the more Western countries, and was told that real opium is very hard to get here. His/her friend bought some, but now believes it to have been black tar heroin. SWIM isn't convinced it is. SWIM doesn't know the opiate culture well, so while doing some digging, he came across pictures of black tar opium, which greatly resembles the product SWIM's friend had. What is black tar opium (BTO)? Wikipedia mentions BTO once, but doesn't describe it; Erowid has pictures, but SWIM couldn't find information on it. How does opium become BTO, and what are their differences? Is BTO more commonly sold in the West than normal opium, or is it more likely that black tar heroin is being sold as opium, and SWIM's friend got that?

[cra$h]

swim's experience with opium was black tar. swim smoked a half gram, and didn't even have a comedown, 7 hours later. But the next weekend a kid was selling "opium", and it was heroin. people would smoke a shitload and have some nasty withdrawls, so I guess it's the comedown that's the difference, unless swiy's experienced both already.

[RoboCodeine7610]

While swim was on a vacation in Egypt, he bought a "quarter"(of a gram?) and was told to dissolve it in tea with no sugar.

He did so but had absolutely no effects up to 1 hour after ingestion so he went to bed.The next morning it was really hard for him to wake up and when he did he was REALLY dizzy and was nodding really hard and was having numerous "dreams" before waking up only to nod again.
That was about 8 hours after ingestion so he guesses the stuff was pretty strong...

And as a side note:
Swim had dihorrea in the morning instead of constipation, really weird.