Metallic properties of iodine
Iodine is a metalloid. Metalloid elements have one or more allotropes with properties intermediate between those of a metal and a nonmetal.

Metals are lustrous, ductile, and conductive of heat and electricity.

Nonmetals are matte, brittle, and insulators.

Metalloids may be semiconductors, like silicon, germanium, arsenic, and carbon (graphite). They may be lustrous, but brittle, like iodine and tellurium.