I saw someone do a demonstration once, they took a box of "iron-fortified" breakfast cereal, dumped it into a bowl, then ran a magnet through it. The magnet picked up some of the dust from the bottom of the bowl, that dust being the tiny iron particles that were added to the cereal to "fortify" it.
Many years ago I ripped a large number of DVDs, several hundred if not into the thousands, and the vast majority were dual-layer. Very few commercial movie releases were on single-layer disks, at least in the US. It sounds like you may be in another country so your experience may be different but where I am dual-layer disks were far more common.
I put them in quotes as the word has no objective meaning as applied to a breakfast cereal, it's simply a marketing term. I did not intend to imply that ingested iron particles are not a valid source of iron for human biology.