I was going to ask you whether you could cook with them but someone else commented on that saying you could get copper poisoning. (edithandevelynvintage.com)
The symptoms of copper poisoning are usually not evident until the damage is already done to the liver, which can not be reversed. (wagwalking.com)
Many people, including the author, felt they were becoming more «spiritual» on a vegetarian diet, when in fact it was just copper poisoning! (myersdetox.com)