This may indicate a condition called de-zincification. This is when the zinc, through age, separates from the copper in the brass, causing pitting and pink staining. This happens with age and is hurried up if, in the past, a polish with ammonia in it has been used. When we receive items in this tarnished state (as in the photo to the right), the first thing we do is put them through a chemical cleaning process to remove this extremely hard tarnish. We have to be extremely careful with the cleaning process and (unlike electroplaters) only remove enough of the tarnish to facilitate the polishing process. Until this is done we have no idea of the condition of the brass, or whether the items are restorable or not. Another problem that arises is very fine stress cracks, which only show up after the chemical cleaning process.
Contact Kathy for your restorations