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

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

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.

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.

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.

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.

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

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

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.