It’s really weird, how popular culture keeps using diamonds as (usually ill-gotten) currency. In reality, they are pretty terrible for the purpose, and I think most people are aware of that.

Buying diamonds has always been expensive, but selling them, is another matter, entirely.

Also, deBeers invented the diamond wedding ring fairly recently. My mother’s wedding ring was a big-ass sapphire. If you look at classical wedding rings, they are often non-diamond stones.

I think most of that perception comes from cultural depictions of jewel thieves. If you're stealing the diamonds, not paying for them, then they're a very concealable and conveniently value-dense. It doesn't matter to a jewel thief that the tiny little shard of shiny gravel was originally purchased for many thousands of dollars. What he cares about is he can hide it anywhere and get hundreds of dollars for it. Much better than stealing TVs.

> Also, deBeers invented the diamond wedding ring fairly recently.

The DeBeers campaign that boosted the already significant popularity of diamond engagement rings was in 1947. I don't think diamonds or other gemstones on wedding (as opposed to engagement) rings have ever been a major thing (though I'm sure some people do that.)

Tiffany, I think, did a big push a few decades before that did a lot for the popularity of diamond engagement rings among the middle class, and diamond engagement rings had been popular among the upper class since something like the Victorian era.