Answer
(Fatwa: 435/388/D=1433)
You can give jewellery in mahr but you should inform her. But, if money was fixed in mahr and later you changed your intention and decided to give jewellery in mahr then too you should tell her clearly that you are giving her these jewelleries in return of money. If the wife accepts it then it is right. The main thing is that whatever is fixed in mahr it should be paid, whether it is cash or in form of gold, silver, kind, vehicle, animal etc. In case one is giving something else other than what was fixed then it is necessary to inform in clear words and it is also necessary that the woman accepts it.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband