Hi Lubek, welcome to Bluelight
You might want to read the guidelines. The guidelines for this forum, Basic Drug Discussion, can be found in my signature below.
We don't use "SWIM" here, it doesn't really offer you any protection and it makes posts harder to read. We also don't do drug identification. We can't tell what your substance is or if it is in fact real heroin just from a written description. Do a Google image search for tar heroin and you will see that it comes in many different textures and colours.