Zeacon69
Sansui-G-
copper turns teal/green/blue when it corrodes, look at old pennies, i let my smith and wesson 357 mag stainless steel revolver sit for one day without cleaning it after shooting jacketed soft points (jackets are made of copper), when i ran the swab down it it picked up the copper that turned teal, i beleive that the au d11 pic lost some protective coating (im guessing) 