Storytime. I was working in my first industry gig, still a student -- the exploration office for a major nickel mine. I had been hired for the summer along with a bunch of other students. The following happened to another student.
She was a Master's student who was given the job of sending drill core coming into the exploration warehouse to assay. Not cutting the core -- but selecting the samples, doing the paperwork etc. Her supervisor, however, immediately went on vacation, so she didn't have enough training. Worried that she wasn't checking the right assay boxes, she just checked all of them. The samples came back so high in platinum and palladium that the nickel would have been a smelter credit. No one at the mine had ever done an assay for platinum or palladium before in the 60+ year history of the mine. This triggered a huge flurry of activity while they assayed a bunch of other things, including their tailings. 2008 happened (and the exploration economy faltered) so I don't know what came of it because I moved on. But, yeah, mine waste isn't always waste ;)