All perfect praise be to Allah, The Lord of The Worlds; and may His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
It is disliked for a man to wear a ring made of a precious metal such as diamond and corundum since there is no evidence in Sharia forbidding that ;whereas, wearing a ring made of gold is forbidden. Kindly refer to {Moghni Al-Mohtajj(1/137)}.
As regards chains and bracelets, it is impermissible for a man to wear them regardless of the metal they are made of, because doing so makes him imitate women. Abu Hurairah(May Allah be pleased with him) said, "The Messenger of Allah(PBUH) cursed a man who puts on the dress of women, and a woman who puts on the dress of men."{Ahmad}.
The Eminent scholar An-Nawawi(May Allah be pleased with him) said, "Our fellow scholars said: "There is a consensus that a man is permitted to wear a ring made of silver; whereas, other adornments made of silver, such as bracelets, chains, and the like are definitely forbidden, according to the opinion of the majority of the Muslim scholars."{Al-Majmou`(4/444}. And Allah knows best.