All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions
It is permissible for a woman to wear whatever jewelry she likes as long as she is not extravagant, whether it is gold or silver or else, and whether they are adorned with cowrie shells or else, or not adorned at all. Allaah says: (interpretation of the meaning): {It is He Who has created for you all things that are on earth; ….}[2:29].
The Prophet said about gold and silk: "These two things are prohibited for the males of my nation and permissible for its females." [Ibn Maajah]. The Prophet also said: "Wearing silk and gold has been made lawful for the females of my nation and unlawful for its males." So it is forbidden for men to wear gold as the Prophet said: "Unlawful for its males." However, it is permissible for men to wear silver rings, as Anas said that the Prophet "Wore a silver ring in his right hand." [Muslim]
Nevertheless, the people of knowledge differed in opinion regarding a man wearing precious jewelry other than gold and silver. The sound opinion is that it is disliked because this can be considered as imitating women and being extravagant, while "The Prophet cursed men who imitate women." [Al-Bukhari]. It may even be forbidden if by wearing jewelry a man really imitates women or imitates the dissolute and corrupt people.
Allaah knows best.