Angel's Wings

An Angel's Wings are the wings of an angel.

Angels can display their wings as a sign of their status as an angel by summoning a shadowy form of them. When Angels die as a result of being stabbed by an Angel Blade, shadows of their wings are burned into the surface on which their vessel is lying, as seen in the opening of "On the Head of a Pin" when Castiel finds a female angel dead on a street, and again when Anna kills Uriel and when Zachariah and Gabriel were killed.

An angel may display its wings through Astral Projection to intimidate enemies: Castiel displayed his wings to intimidate Raphael after getting the Angelic Weapons and then when he was about to smite Crowley.

Gadreel's astral projection showed broken wings and when Gadreel killed angels using the Horn of Gabriel, broken wings were scorched into the ground behind them. When Castiel regained his grace, he regained his wings as well, though like Gadreel, they were still broken.

Metatron's spell that cast out all angels from Heaven burned and destroyed every single angel's wings. Some higher angels like Castiel and Gadreel kept their wings, but they were broken instead of burned.

The spell doesn't appear to have affected the Archangels and Grigori since they were able to teleport and Lucifer was able to time travel, which required wings. This means all angels save for Michael, Lucifer and probably Grigori have broken wings.

In "Rock Never Dies", a fossilized black feather from Lucifer's wings is shown to be capable of restoring his vessel, though only temporarily.

Trivia

 * Mark Pellegrino described Lucifer's wings as "hot pink and sparkly".
 * In lore, angels weren't originally portrayed as having wings. The tradition that angels possessed wings began around the early 20th century.