I suspect it's zhu lu, which is commonly called gunpowder green or Chinese gunpowder. Gunpowder was historically tightly rolled like that to help preserve freshness on the long trip to the west. Some customs fellow remarked that it looked like gunpowder and the name stuck.
Gunpowder isn't something that gets a lot of fans around here, but I've found some that's pretty decent. If you like it then that's all that matters. You might try to find out where it came from if you want to get more, however, as gunpowder can range from smoky to peachy to thick, sweet, and mild. I'm sure there are gunpowders with different profiles as well.