Iodine is a heavy, lustrous violet-black solid that sublimes into a violet-blue gas when heated. Sublimation is a process by which a substance transitions from a solid into a gas without first turning into a liquid.
The violet-blue vapor produced after iodine is heated has a strong acrid odor that is extremely irritating to the nose and eyes.
Iodine dissolves in water and in other solutions, such as carbon disulfide and chloroform, to form purple solutions. When iodine vapors cool, they form metallic crystals. Iodine melts at 113.5 C (236.3 F), boils at 184 C (363 F) and has a density of 4.94 g/mL.