Even if silverware is stamped "stainless steel" Touch them with a magnet. I remember when I got into doing this- I proudly brought a good slug of stamped "Stainless Steel" Forks, knives and spoons to the scrap yard, guy hit them with a magnet- steel, shred, crap steel- he said! I even was dumb enough to argue with him- I said "They are STAMPED stainless steel" he said it has an iron content- so not true stainless!