If she wants a diamond despite knowing all the misery the diamond industry spreads, then you should probably just break up
Mining is still dangerous work. The workers are still underpaid. The profits are still stolen by companies that are literally the vestiges of European colonialism.
https://edition.cnn.com/2018/09/03/africa/marine-diamond-min...
None of your comments applies to any of the mines mentioned; Canada, Australia, and the marine operations all abide by OSHA regulations and pay good wages.
If you want to make a specific comment about conflict diamonds, for example, it pays to be aware that it's not just mining that sucks in war zones .. quality of life is pretty poor all around.
There are mines I wouldn't work in, there are many mines I'd have no issue working in.
Which mines have you you worked in and what was your role?
Granted, maybe there are good mines out there, but I still think commercial extraction of resources is almost surely damaging to its surrounding environment. You can justify that for some useful material, but it's hard to justify it for diamonds.
Mining in general I view as a somewhat neccesary evil that needs to made humane for workers and as something driven by unthinking consumption, the remedy lies upstream from mines in the mindsets of populations that demand resources.
Resource extraction can't be eliminated but it can be reduced, as should population numbers.
Doesn't it matter what he thinks?
Does "If she wants to eat meat despite knowing all the misery the food industry spreads, then you should probably break up" sound like a good idea to a guy who isn't vegan/vegatarian/etc?
And yeah of course what he thinks matters too. If you're both awful people then you deserve each other.