What is the Sharia ruling regarding the wife's gold (dowry necklace), the deferred dower, and the list of movables, especially furniture purchased by the husband, in the event of the death of both spouses in an accident where it is not known who died first, and there is a desire from the wife's family to take all the contents of the list and the gold?

Inheritance requires the heir to be alive after the death of the inheritee. If the death of one spouse before the other is confirmed, the one who died first does not inherit, and the one who died later is among the heirs of the first. However, if the date of death of each is unknown, neither inherits from the other, and the estate of each is divided among their respective heirs. Consequently, if the wife's death before the husband is confirmed, the husband inherits from his wife; otherwise, there is no inheritance between them.

As for the wife's possessions such as gold, deferred dowry (mu'akhkhar), and movable items, they belong to her heirs. If the apartment and other items were purchased by the husband as part of the dower (mahr) or if he gifted them to her and she took possession of them, then they are the property of the wife and her heirs. Otherwise, they are the property of the husband.