Can medallion fade without polishing?

Hello forum,

Today I found a Constellation that made me surprise. The case looked sharp but there were only 6 stars. If I had seen only the back case, I'd have thought it was overly polished. The seller described "The stainless steel case is in very good original unpolished condition with a gold case emblem (faded stars)." Was it possible? and how?

Thank you.