I was working the shred pile at a scrap yard (the area where to public comes to drop off scrap for money).
I'm used to junkies, regulars, random people but this was a different experience.
They showed up in a little blue car and I start walking over to them. Right as I'm walking over I get called on the radio from the other department (the guys who take copper, aluminum, etc..) the other department informs me that these guys just tried to sell them rocks so watch out.
So I finish walking up to their car and do my basic “hey guys how are you doing? What do you have for me?”. They respond with “oh man we got this whole bag of metal rocks, those guys in other department can't even tell what it is but we know it's steel so we came to you”. I'm like “ok… Let's see”. They head around to their trunk and pull out a cloth Dollarama bag filled with rocks. I grab one, pull out my magnetic, and show them it's not magnetic. They start getting hostile so I try a few more. A few of the rocks were actually mildly magnetic which is when I realized what this was. They had found a pile of slag from a foundry that was mostly nonferrous material so some of it was magnetic but they had also thrown actual rocks in to get more weight. I informed them that most of these are rocks and if I bought it as slag they wouldn't even get a dollar for their little bag.
That's when the next guy pops out of the car. He starts pulling up his giant pants and telling me “man man like this bag be fucking 20 pounds man man. Just give us $10 for the bag common man it's magnetic just give us money”. I then try to explain that I'm not the person who gives you money, I'm the person who tells you what the product is and then tells the office and the office pays you. They're not taking no for an answer so I call my supervisor over. My radio is always maxed out so they hear him say “we'll use the mag sweeper (it's like a magnet on wheels I use to clean nails off the ground) and whatever sticks we'll be as slag but they probably won't even get a dollar”. So I go grab the sweeper and barely any are sticking to this giant magnet so I say there's no point in buying this. They freak out again so I radio the supervisor again and he hears them bitching at me. Fucking supervisor comes right over, grabs a hammer and their rocks, and starts smashing the shit out of it and goes “steel doesn't smash like that guys, we're not paying for it”. Then walks off xD
They leave all pissed but still leave the bag. I radio the office to let them know to deduct 20lbs of garbage from their total weight after they go on the scale.
Never heard the end result but that's my experience with it.