Is it permissible to sell a piece of gold found in the street a year and a half ago and use its price to prepare for marriage?

A lost item (Luqatah) must be announced for a full lunar year if it is not trivial, and the obligation to announce does not cease after a year without announcement. If the item is valuable, and the finder leaves it, knowing it is forbidden to do so, he is sinful and must repent. The most sound opinion is that he must announce it and publicize it in places where its owner is likely to be found, such as mosques and markets. If the owner comes and identifies it, it must be handed over to him. If a year passes and the owner does not appear, the finder may benefit from it or give it as charity on behalf of himself or its owner. If the owner later appears, he is given the choice between its value or the reward of the charity.