If a man gives his wife gold that is not part of the mahr, if his intention was to give it as a gift, then the gold has become her property, and it is not permissible for him to take back this gift.
Al-Bukhaari (2589) and Muslim (1622) narrated that Ibn ‘Abbaas (may Allah be pleased with him) said: The Prophet (sa) said: “The one who takes back his gift is like the dog which vomits then goes back to its vomit.”
Al-Bukhaari (2622) also narrated: “We are not like the bad example of the one who takes back his gift; he is like a dog that goes back to its vomit.”
This hadeeth indicates that it is haraam to take back a gift.
The scholars of the Standing Committee for Issuing Fatwas were asked: A man gave his entire house and all the furniture in it as a gift to his wife; can he take back his gift, and how?
If the wife has not taken possession of what her husband gave her in a way that is customarily regarded as taking possession of something, then he may take back his gift. Hoever, this is not regarded as dignified conduct, because the Prophet (blessings and peace of Allah be upon him) said: “The one who takes back his gift is like the dog that goes back to its vomit.” If she has taken possession of it in a manner that may be regarded as attaining ownership according to custom, then it has become her property and he cannot take it back, according to Islam, except with her consent. Nevertheless, if he takes it back after she willingly returned it to him, that is contrary to decency and dignified conduct. If they disagree concerning the gift and what is regarded as taking possession of it, then the matter should be settled in the sharee‘ah courts.
End quote from Fataawa al-Lajnah ad-Daa’imah, 16/247
Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd ar-Razzaaq ‘Afeefi, Shaykh ‘Abdullah ibn Munay ‘
But if he gave her the gold as a loan, to use it and wear it as an adornment, and it is still his property, then this gold belongs to the husband, and is not the wife’s property, so he may ask her to return it to him.
And Allah knows best.