What is the ruling on wearing copper jewelry? And should a person performing the prayer say the Taslim upon concluding the prayer while praying Tahiyat al-Masjid, or should he directly join the congregational prayer?

Wearing a copper ring is disliked for men and women according to some scholars. The Maliki school has two opinions regarding it: disliked (makruh) or forbidden (haram). As for other adornments made of copper, such as bracelets and necklaces, wearing them is forbidden unless there is a religiously recognized benefit, such as for necessary medical treatment.