Cinnabar is the ore of mercury. It has a long history (as you can tell from its derivation). The pigment vermilion, a bright red, is ground cinnabar, and in China, only the emperor was allowed to use this for writing.
Mercury (sometimes called quicksilver) is a liquid metal. It is used for thermometers. It's named after the Roman god Mercury, who was the messenger of the gods, and flew with winged sandals. A blob of mercury moves very fast, since it doesn't "wet" a surface, like water, and so doesn't stick to it. (Since mercury is poisonous, I advise that you don't try this!) The planet Mercury moves very quickly through the sky.