It is not permissible to deal in jewelry that bears images of animate beings because of the general meaning of the proofs that prohibit producing and hanging images. The Prophet (peace be upon him) stated:
Allah and His Messenger made illegal the trade of alcohol, dead animals, pigs and idols.
Idols include any image of animate beings or whatever possesses a soul, even if they are engraved on jewels. This ruling applies whether the purchaser is a Muslim or not.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.