Ping Eye Two Be-Copper Sand wedge corroded by Sulfuric Gas emmited by Toxic Chinese Imported Drywall Installed in my home that Knauf Drywall company has done nothing about for 3 years now. This is my advertising for them!!!!!!!! This is Corrosion not Patina, If you rub your finger on it you get charcoal on your finger. You should see all the silver items and the airconditioner coils.....Again Knauf Brand Drywall is the cause...Beware!!!!!