Amulet (Taaweedh)

Uqbah ibn 'Amir narrates that the Prophet (Blessings and peace be upon
him) said: "If anyone wears an amulet (taaweedh), may Allah not help
him in fulfilling his wish. If anyone wears a sea-shell around his
neck, may Allah give him no peace."

Narrated by Ahmad and Al-Hakim.