Speak for yourself. I frequently carry a diamond pick and blowtorch in my trouser pocket.
you make this joke, But there are lots of people who do have diamonds in their pockets
Diamonds are the most found gemstone that is placed on rings, especially engagement and wedding rings. it is not uncommon for rings to be taken off and placed in pockets or other places that one may also store their phone, Such as bag, pocket or purse.
SO, as much a joke you're trying to make of it, it's not as uncommon as you think.
There are also tiny bits of silica that may lodge in your pockets that are also rated at Moh 10 that could scratch your phone without you even realising it.