In an age when you can get just about anything online, it's probably no surprise that you can buy a diamond-making machine for $200,000 on Chinese eCommerce site Alibaba. If, like me, you haven't been paying attention to the diamond industry, it turns out that the availability of these machines reflects an ongoing trend toward democratizing diamond production—a process that began decades ago and continues to evolve.

The history of lab-grown diamonds dates back at least half a century. According to Harvard graduate student Javid Lakha, writing in a comprehensive piece on lab-grown diamonds published in Works in Progress last month, the first successful synthesis of diamonds in a laboratory setting occurred in the 1950s. Lakha recounts how Howard Tracy Hall, a chemist at General Electric, created the first lab-grown diamonds using a high-pressure, high-temperature (HPHT) process that mimicked the conditions under which diamonds form in nature.

Since then, diamond-making technology has advanced significantly. Today, there are two primary methods for creating lab-grown diamonds: the HPHT process and chemical vapor deposition (CVD). Both types of machines are now listed on Alibaba, with prices starting at around $200,000, as pointed out in a Hacker News comment by engineer John Nagle (who goes by "Animats" on Hacker News). A CVD machine we found is more pricey, at around $450,000.

An image of a "HPHT Cubic Press Synthetic Diamond Making Machine" made by Henan Huanghe Whirlwind Co., Ltd. in China.Henan Huanghe Whirlwind Co., Ltd.

 A photo of part of a "HPHT Cubic Press Synthetic Diamond Making Machine" made by Henan Huanghe Whirlwind Co., Ltd. in China.Henan Huanghe Whirlwind Co., Ltd.

 A photo of a factory full of HPHT Cubic Press Synthetic Diamond Making Machines, made by Henan Huanghe Whirlwind Co., Ltd. in China.Henan Huanghe Whirlwind Co., Ltd.

Not a simple operation

While the idea of purchasing a diamond-making machine on Alibaba might be intriguing, it's important to note that operating one isn't as simple as plugging it in and watching diamonds form. According to Lakha's article, these machines require significant expertise and additional resources to operate effectively.

For an HPHT press, you'd need a reliable source of high-quality graphite, metal catalysts like iron or cobalt, and precise temperature and pressure control systems. CVD machines require a steady supply of methane and hydrogen gases, as well as the ability to generate and control microwaves or hot filaments. Both methods need diamond seed crystals to start the growth process.

Moreover, you'd need specialized knowledge to manage the growth parameters, handle potentially hazardous materials and high-pressure equipment safely, and process the resulting raw diamonds into usable gems or industrial components. The machines also use considerable amounts of energy and require regular maintenance. Those factors may make the process subject to some regulations that are far beyond the scope of this piece.

In short, while these machines are more accessible than ever, turning one into a productive diamond-making operation would still require significant investment in equipment, materials, expertise, and safety measures. But hey, a guy can dream, right?

The great diamond glut

Sometimes a Hacker News comment is worth more than its weight in gold (or diamonds), and John Nagle, who developed Nagle's Algorithm for improving the efficiency of TCP/IP networks in the 1980s, posted a great one in response to Lakha's article. It contains interesting facts about diamonds, with sources, that are worth relaying for anyone curious about the current state of diamond production.

One notable development comes from De Beers, the diamond corporation known for its dominance in the natural diamond market. Through its R&D operation Element Six, the company is now capable of producing synthetic diamonds with flaw levels in the parts per billion range. This purity level far exceeds what's necessary for jewelry, entering the realm of high-tech applications. Element Six has even created diamond windows for lasers up to 10 cm across, showcasing the potential for large, extremely pure synthetic diamonds.

On the natural diamond front, there's been a surprising breakthrough. Nagle points out that the industry has developed an industrial X-ray system to examine rocks before crushing, helping to preserve large diamonds that might otherwise be broken during extraction. This technology has led to some impressive finds, including a 2,492-carat diamond discovered last month. The sorter for this job comes from TOMRA, a company known for high-volume sorting systems used in recycling and food processing.

Interestingly, this improved extraction method has created an unexpected challenge: a glut of giant diamonds too large for typical jewelry use. The glut hasn't been helped by automation in the diamond industry. Nagle notes that the finishing processes of cutting and polishing diamonds has been automated, with much of the machinery for these tasks coming from China and India.

As a result, Nagle says that lab-grown diamonds are now something you can buy by the kilo, in plastic bags, which—big surprise—we also found on sale through Alibaba, although the price varies highly based on whether you are stocking up on industrial diamond grit for grinding and polishing or buying glittering round brilliant cut specimens for jewelry.

This image starkly contrasts with the traditional perception of diamonds always being rare, precious stones, each individually valued and handled with care. As many people now know, that concept was created by De Beers' marketing department in the 1930s to sell diamond engagement rings.

While the glut of diamonds is a challenge for an industry calibrated around the idea that diamonds are rare, precious stones, perhaps the low price of synthetic diamonds may lead to industrial applications that were impractical in the past. Who knows—maybe one day, Apple will ship a completely unbreakable iPhone with a diamond glass screen.