Bought my wife a big old man made diamond necklace in the early 2000s from an ad in Popular Science. She was aware but loved it. She especially liked when other women would ask her if she was afraid to wear it out, for fear of losing it. Best $70 I spent.
At this point you're not paying money for a diamond, you're paying money for a certificate.
If you want to know how much a diamond is really worth, go to any jewelry store and ask them to appraise the resell value of your natural diamond ring with certificate and all, no matter how much you paid for it, they're probably going to tell you only the precious metal setting is worth any money, and the rock itself is utterly worthless the second you received it.
A Veblen good is a type of luxury good, named after American economist Thorstein Veblen, for which the demand increases as the price increases, in apparent contradiction of the law of demand, resulting in an upward-sloping demand curve. The higher prices of Veblen goods may make them desirable as a status symbol in the practices of conspicuous consumption and conspicuous leisure. A product may be a Veblen good because it is a positional good, something few others can own.
That said, part of the problem with lab-grown diamonds is that they're not competing against a rare commodity. They're competing against a powerful vertically integrated cartel. There isn't any real diamond shortage, just a supply-side monopoly. There isn't a natural high demand for diamonds, just a market saturated with aggressive advertising. There isn't a wholesale diamond exchange judging the rocks objectively on their quality, just a series of elaborate marketing gimmicks and scammy sales goons trying to upsell you.
Diamonds have always been a racket. The one blessing of manufactured diamonds is that they're no longer a racket putting market pressure on industrial grade diamond equipment. But the jewelry exists to separate gullible superficial status-fixated people from their money. Ethics was never part of the equation.
I like diamonds, my wife calls me a magpie. I buy her jewelry so I get to look at it while she wears it. That being said, I only buy jewelry with artificial diamonds for my better half. She jokingly reacts affronted when I tell her, with an incredulous face she will go "What? No children died for this? Some husband you are!"
It was weird to me, when I was looking for rings and jewelry that there are gems that have a higher brilliance and luster than diamonds (and unlike super-fancy bright glass is actually robust enough for typical use). And yet, the folks that want diamonds want diamonds. Since around 2016 after seeing the Mnuchins in the news, it felt like conflict diamonds and slave-mined diamonds are in.
I'm not even sure where the need for an expensive gem stone came from, diamond or otherwise.
My wedding/engagement ring came from an artist and the bands are sculpted and fit together. It's beautiful and I never have to worry about the stone falling out of the setting, plus it was in our price range. Gem stones can be nice, not arguing against them, but rings without them can be just as pretty and more affordable.
I gave my wife a natural diamond engagement ring, but it belonged to my great-grandmother, so I felt that it was ethical enough. You can't really do much about suffering 120 years ago (or whatever it was) and probably everyone involved in making that ring was treated like shit in one way or another because it was 1904 and everyone who wasn't white, male and rich suffered.
The suffering has absolutely nothing to do with their value. It’s shit like this dilutes the water of topical debate. But why does that matter when you can hitch your agenda to a sting of words that sound deep and impactful.
Here is a simple and easy to understand unbiased explanation of why diamonds are valuable.