Bezel

The bezel on that old iPhone model was white.

Source: tatoeba (8851209)

A smartphone bezel is the plastic or metal border on its front surface, surrounding the screen.

Source: tatoeba (8851212)

“There,” she went on, “it must be one like to it, and yet never did I see one like to it, for thereto hung a history, and he who wore it prized it much. But the scarab that I knew was not set thus in the bezel of a ring.

Source: wiktionary

Modern smartphones have very thin bezels.

Source: wiktionary