I purchased a jar type with a tumbler as a lid on Sunday the 27th March at a Sai Sankeet hotel on the highways at Ambur. Today being the 2nd day of purchase , I noticed dark patches at the bottom and on the inner side also. The copper shinning has gone in some places. I am sure this copper coating will disappear soon. If you require, I will forward the WhatsApp video of the jar for your perusal. May I have your response please..