Reference: al-Bid’u wal-Muhdathaat wa maa laa Asla lahu – Page550
Fataawa Manaar al-Islaam – Volume 1, Page 45
Question: The ruling regarding attaching a [miniature] copy of the Qur.aan around the neck.
Response: It is impermissible to attach a copy of the Qur.aan [to hang] around the neck, neither as a form of jewellery nor other than it since this is [regarded as] an innovation which [none of] the Companions (radhi-yAllaahu ‘anhum) did.
Additionally, it is impermissible for a person to hang it around the neck in order to relieve himself of trials and tribulations or to prevent them, because this was not done by the Prophet ﷺ and nor any of the noble Companions.