Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
The necklace in a dream for a woman is a husband or a son. For a man, it is authority, a covenant, or a trust. A necklace of pearls indicates knowledge and the Quran. The breaking of the necklace indicates the loss of position or a problem with the wife or son.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
The necklace indicates beauty and adornment. Whoever sees a necklace of jewels around his neck will be entrusted with a great trust or gain useful knowledge. For men, a necklace indicates a debt on their necks.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
The necklace is interpreted as a covenant and a promise. A beautiful necklace indicates good fulfillment of the covenant. Whoever sees his necklace break and get lost has broken his covenant or lost his trust.