How diamonds are made

99% of all diamonds by mass are industrial diamonds. But they are so inexpensive that they only account for 3% or the revenue.

The jewelry is the remaining 0.8% by mass, and it is split roughly equally between the natural and synthetic stones by mass, but with about 80% of the revenue going to the natural stones.

Here is a very good video showing how large poly-crystalline industrial diamonds are made in the USA: https://www.youtube.com/watch?v=6o5RprIJmfA

China has their own, slightly different flavor of this machine, the cubic press. These machines are manufactured in thousands and cost about half a million USD each. They are used to produce both industrial and jewelry quality diamonds: https://www.youtube.com/shorts/cED0TjwKUDM https://www.youtube.com/watch?v=5cnEVb7aPfM

The original machine was invented by a guy at General Electric: https://en.wikipedia.org/wiki/Tracy_Hall

Since this is HN, as an aside, Surat (the city mentioned in the article where the gems are polished) holds the dubious record of being the last major city in the world to have had an epidemic of the bubonic plague[1] back in 1994. They took the opportunity to really clean up the place after that.

Today, Surat is known for another distinction: the world's largest office building[2] (even larger than the Pentagon).

[1] https://en.wikipedia.org/wiki/1994_plague_in_India

[2] https://en.wikipedia.org/wiki/Surat_Diamond_Bourse

> From here, there are two rounds of sorting: gem quality and industrial grade. Most of mined diamonds never become jewellery. They go to cutting tools, drill bits, and grinding equipment.

For industrial use synthetic diamond is actually quite cheap now. The vast majority of industrial diamonds used today are synthetic and they've been affordable since the 1950s (?). Industrial-grade synthetic diamond grit or powder can cost as little as a few dollars per carat. This makes it far cheaper than mining natural diamonds for the same applications.

De Beers built and has abandoned a very large CVD gem diamond synthesis in Oregon. This was their LightBox operation. They've transferred it to Element Six to rid the parent (De Beers) of the money sink, probably as a touch-up before a sale.

There was a fire sale of LightBox diamonds a few months back. I picked up 3 diamonds, all brilliant cut: 3ct. white, 2ct. pink, 2ct. blue. Total for the three was $600.

Well, that goes for some diamonds.

There's another kind that are made by man. In recent years -- over the past four or five years -- there has been an explosion in synthetic diamond production, largely driven by factories in China and India. There are a lot of those factories (spurred by the relatively easy availability of the necessary production-line equipment) and they're all in cutthroat competition with each other, so there has been a race to the bottom on price.

You can get huge, very high-quality diamonds now for a fraction of what they used to cost. Like 95% off. It's crazy.

And how diamonds are grown: https://en.wikipedia.org/wiki/Synthetic_diamond

There was a discovery in 2024 on how to make diamonds under atmospheric pressure.

https://en.wikipedia.org/wiki/Synthetic_diamond#Crystallizat...

I thing that method can only produce small crystals, although I think the authors said something along the lines that it would probably be possible to further evolve the method to make them bigger.

Here’s a good video I found on synthetic diamond production in the USA:

https://youtu.be/6o5RprIJmfA?si=RuMEdtqWNyDyf6q-

I wish articles/domains like this one, which are accessible, playful, informative, short, and with images would be easy to identify in HN.

That would be something worthwhile to share with children aged 8-12 who love learning new things.

Was hoping for a walkthrough on how chemical vapour deposition (cvd) works. That stuff is fascinating, and it's how most diamonds are (man-)made

One more fact that might be interesting about natural diamonds: not all of them are extracted by digging mines; the oldest way of extracting diamonds is by sifting through alluvial deposits.

This method originated centuries ago in India. In fact, until the 18th century, this was the only known method. The most famous origin of alluvial diamonds is the Godavari-Krishna river delta in the old Golconda Sultanate. This particular site was exhausted about 200 years ago, making Golconda diamonds especially precious now.

Anyone know how those MS-paint-like vibrating gifs were made?

That's not how Superman did it.

Amazing design. Very interactive!!