Ibrahim narrates from Sayyiduna Ibn Mas'ud (may Allah be pleased with him) that a woman asked him about her jewellery: is there zakah on it? He said: "When it reaches (the value of) two hundred dirhams, pay its zakah." She said: I have some orphans in my care; may I give it (the zakah) to them? He said: "Yes."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9560