Okay, guys, a couple things:

-First, leaded glass is still common nowadays; they don't put lead in window glass anymore, but any high quality cut crystal is made from leaded glass.

-Second, Pyrex is not a coating. They cool the glass down very slowly after forming it so it cures very hard and strong, sort of like tempering steel. There's no coating-- you're thinking of safety glass.

-Finally, the black residue is from the lighter. Butane is, chemically speaking, C4H6. When burned (2C4H6 + 11O2 --> 8CO2 + 6H2O), the IDEAL results are just gases-- carbon dioxide and water vapor. However, the reaction isn't perfect because of impurities in the butane and other environmental factors, so you get other byproducts--namely, carbon. That black stuff is just carbon residue left on your pipe by the flame.

Hope that clears things up.