Oh, by the way, Laurel, your definition needs to be a bit more specific. Black smokers spew metal sulfides which precipitate out when they come into contact with the colder ocean water. The hydrothermal vents that are a little bit cooler are white smokers, which spew metal sulfates. Those are white. Speaking of chemistry, I am keeping the stuff organized. Today (under the supervision of Mrs. Jones, of course) we did an awesome reaction that Mrs. Jones pointed out to me. It's called "zinc pyrotechnics" and it's really cool. Mix 8g very fine zinc dust, 8g ammonium nitrate, 1g ammonium chloride, and crush them up together. Put them in a 50 mL beaker inside a fume hood with no other flammable substances. Add two drops of water and close the fume hood front. Watch the sparks fly and the flame foom! Use only under adult supervision.