Iodine

chemical element · purple · essential nutrient

A stunning purple element. Iodine is dark and shiny as a solid, but when it gets hot enough (114 degrees Celsius), it melts into a glowing deep purple liquid. If you heat it even more, it turns into a beautiful violet gas that floats away into the air.

Discovered in seaweed ash. A French chemist named Bernard Courtois found iodine in 1811 while burning seaweed to make gunpowder. He noticed purple crystals forming in the ashes and realized he had discovered something completely new.

Named for its color. Two years after discovery, another scientist named Joseph Louis Gay-Lussac gave it the name 'iodine,' which comes from the Ancient Greek word for violet. The name stuck because the element is such a striking purple color.

Your body needs it. Iodine is essential for your thyroid gland, which controls how your body grows and gets energy. You can get iodine from foods like fish, eggs, and salt that has iodine added to it.

The heaviest stable halogen. Iodine belongs to a family of elements called halogens, and it is the heaviest one that stays stable and doesn't break apart on its own.