Diamonds Are Bullshit (2013)

Not entirely OP. If you're using them for industrial purposes, they are very hard. And if you're using them for jewelery, the same logic applies.

So go ahead and get a giant Cubic zirconia or whatever if you want to show that you've got a partner you care about, just don't make people live in literal slavery, shitting into a mesh filter after their shift in the diamond mine so you can show off that three months of salary is in your "work".

The people you'll still want by your side a decade or two later would take that money and get on a flight to Tokyo, not wear it on their hand and then feel a need to tote around a giant purse with a hand cannon in it and live in a house with a literal panic room because they've so thoroughly pillaged society that the barbarians might show up at the gate.