What is the ruling regarding a woman who deposits her money with a gold merchant and then chooses from him later, whether she specified the type of item beforehand or not?

It is permissible for a woman to place a sum of money with a jeweler until it reaches a certain amount, then execute a sales contract for the value of this money, and receive both considerations [the gold and the money] at the session of the contract. There is no difference whether she specifies the type of item she wishes to purchase or not. However, to buy a necklace or an earring without specifying its shape and without immediate possession, this is prohibited because it constitutes selling gold for deferred payment, and due to the presence of uncertainty (jahalah) in the sold item.