coffee gold

I was drinking black coffee in the cafe near my school during a free period. It was in a cheap styrofoam cup, the kind that tends to infuse its contents with the taste of synthetic material. I was doing math homework with one hand and holding the coffee with the other, occasionally blowing on its black surface to make it drinkable. I glanced at it and noticed a ring of bubbles around the edges of the top of the liquid. At first they looked like the brine on the side of an old ship; bulbous, bunched together in small clumps. I looked closer and blew on the drink a little more, and they began forming neat rows around the rim of the cup. They looked golden, and solid, but would always float back to the top of the coffee if they fell of the styrofoam wall.