It is permissible for a woman to show some of her jewelry if it is difficult for her to keep it hidden, for example rings if she does not cover her hands. It is permissible for her to show them according to the opinion of some of the scholars among the companions and those after them, based on the verse of Allah SWA (And do not reveal their adornment except that which is outward (face and hands)). We are assuming the face and hands, and whatever is put on them are considered an adornment. This is the general opinion of the scholars. Some have gone and a sound narration has been reported by Ahmad from of Ibn Masu’d RA that the woman should cover all her body, and this is a precaution if she is in a society which are not harmed by this. As for if she is in the west and the likes, then there is no harm in her showing her face and hands, as there is some space in the ruling, “And we have not made the religion a hardship on you”