Your wife might be special, but there are differences in the signalling of a diamond and gold despite their superficial similarities.

Gold is famous for holding its resale value; so a gift of gold can in theory be unwound to recover the money spent. It is a signal of wealth.

Diamonds cannot be resold, the money may as well have been burned. It is a signal of wealth and commitment. There is also the added bonus that a diamond is not going to be stolen.

>Diamonds cannot be resold.

I wasn't aware of this. What's the rationale?

Try the classic "Have you ever tried to sell a diamond?" article:

https://www.theatlantic.com/magazine/archive/1982/02/have-yo...

They can be sold of course, but you'll get back maybe 50% of the purchase price.

https://www.diamonds.pro/education/sell-diamonds/

Superstition that wearing someone's wedding ring is a bad luck. Probably was similarly manufactured to keep higher demand for diamonds.

More that the people you would take it to have way too many already, and would love to unload them on the next pigeon.

I have got some mileage out of characterizing mined diamonds as symbolizing south-African slavery. At least, my wife didn't want one.

>Diamonds cannot be resold, the money may as well have been burned

I wonder how much money you'd have to actually burn to extract enough carbon to create a decently sized diamond from it

Nothing like what they cost.

Paper is, what, 44-50% carbon by weight? Imagine a ring with the weight of even a small stack of bills.

It wasn't long ago that the paper was worth more than the rock.

But if you burn it, you lose the carbon. Char it instead.

Paper was valuable enough at one point it was considered the traditional gift for first anniversaries in the U.S.

I think the reason that it is the first anniversary gift is that it was not considered valuable (unlike eg silver/gold/ruby/diamond/...)

We used to joke that the 19th anniversary gift theme was packing peanuts.

>I don't know if it's so much about the money as it is something that she just... wanted.

"Thou Art Godshatter".[1] Long-term fitness-increasing Machiavellian plots are encoded as simple human desires. Indeed, social plays like this one work much better if the host thinks it's something they "just want" rather than some grim manipulative scheme to prove your loyalty.

1: https://www.lesswrong.com/posts/cSXZpvqpa9vbGGLtG/thou-art-g...

You don't sound like a very romantic person. There are other things in the world more expensive than diamonds, but she didn't ask him to buy her a skyscraper or Renaissance painting. Different gifts have different meanings, and it's no less logical than different words having different meanings. People associate specific meanings with specific types of stones, flowers, beverages, you name it. You can't substitute "I greatly enjoy the time we spend together" for "I love you."

I must admit to some confusion. I am closely rereading my original comment, and I am failing to find where I suggested that buying a skyscraper is the same as buying a ring.

You're deluding yourself. She could not have at the same time "just wanted" a diamond ring and also "just wanted" you to overpay it 100x times (she cannot notice the difference, so a diamond and a non-diamond ring are functionally equivalent in her eyes, except that you're paying less for one of them)...

It's also worth noting that it's possible to "just want" something for reasons that one isn't consciously aware of (e.g., feeling physically attracted to markers of health and fertility).