An industrial diamond is a diamond used for cutting, grinding, drilling, or other technical purposes rather than jewelry. These stones make up the vast majority of all diamonds produced worldwide. In 2019, global industrial diamond output reached roughly 14.6 billion carats, with synthetic versions accounting for more than 99% of that total. Natural industrial diamonds contributed only about 58 million carats by comparison.
How Industrial Diamonds Differ From Gemstones
Diamonds destined for jewelry are typically transparent, colorless or near-colorless, and cut to maximize light refraction. Industrial diamonds are the opposite in almost every visual respect. They tend to be gray or brown, translucent or fully opaque, and riddled with inclusions and impurities. Many are irregularly shaped, badly colored, or too small to interest a jeweler. The boundary between the two categories isn’t sharp, though. Better-quality industrial stones grade imperceptibly into poor-quality gems, so the distinction is partly about economics: if a diamond can fetch more as a gemstone, it will be sold as one.
What makes a flawed diamond still extraordinarily useful is the property that matters most for industry: hardness. Diamond is the hardest known natural material, rating 10 on the Mohs scale. It also conducts heat better than any other bulk material, with natural single-crystal diamond reaching thermal conductivity values around 2,000 to 2,200 watts per meter-kelvin. For comparison, copper sits at about 380 and aluminum at 240. That combination of extreme hardness and heat dissipation makes industrial diamond irreplaceable in dozens of manufacturing processes.
Natural Varieties
Not all industrial diamonds are alike. Three natural varieties have historically dominated the market, each with a distinct structure.
- Bort is the most common type. It ranges from gray to black, with its dark color caused by inclusions and impurities throughout the crystal. The term also applies broadly to any diamond crystal too flawed, poorly colored, or misshapen for gem use. Bort is widely crushed into abrasive grit for grinding wheels and cutting tools.
- Carbonado is an opaque, polycrystalline form made of randomly oriented diamond crystallites packed together with pores, glassy patches, and highly irregular surfaces. Its toughness made it a prized material for heavy-duty work. Carbonado was used for drilling during the construction of the Panama Canal and remained part of the U.S. strategic mineral stockpile as recently as 1990.
- Ballas is another polycrystalline variety with a distinctive radial internal structure. Its rounded shape and lack of cleavage planes make it resistant to fracturing, which suits it for use in drill bits and wire-drawing dies.
How Synthetic Industrial Diamonds Are Made
Because natural supply is limited and inconsistent, nearly all industrial diamonds today are manufactured. Two processes dominate production.
High-Pressure High-Temperature (HPHT)
This method mimics the conditions deep inside Earth where natural diamonds form. A carbon source, usually graphite, is placed in a growth chamber alongside a molten metal mixture of iron, nickel, or cobalt. The chamber is then heated to between 1,300 and 1,600 °C under pressures exceeding 870,000 pounds per square inch. The carbon dissolves in the molten metal and recrystallizes as diamond. HPHT is the workhorse of industrial diamond manufacturing, producing billions of carats of grit and powder each year.
Chemical Vapor Deposition (CVD)
CVD works at lower temperatures and pressures. A vacuum chamber is filled with a gas mixture of hydrogen and a carbon-containing gas like methane, then heated to about 900 to 1,200 °C. The gas breaks apart, and carbon atoms settle onto a substrate, building up a diamond layer atom by atom. CVD is especially useful for producing thin diamond films and coatings, and it gives manufacturers precise control over the final product’s thickness and purity.
Where Industrial Diamonds Are Used
The most visible application is cutting and grinding. Metal-bonded diamond tools are used extensively for cutting, drilling, and surface grinding of stone, concrete, advanced ceramics, and cemented carbides. If you’ve seen a construction crew slice through a concrete slab or a stonemason shape granite countertops, diamond tooling was almost certainly involved.
In precision manufacturing, diamond tools handle finish turning and boring of cast iron, aluminum alloys, magnesium alloys, bronze, gold, silver, rubber, and plastic at speeds ranging from 100 to 2,000 meters per minute. Single-crystal diamond tools can produce extraordinarily fine surface finishes, which is why the optics industry relies on them for shaping lenses. Diamond is also used to dress (reshape) grinding wheels, keeping other abrasive tools sharp.
Beyond cutting and grinding, industrial diamonds play a growing role in electronics. Diamond’s thermal conductivity of roughly 2,000 W/mK makes it a powerful heat spreader for high-performance chips. In testing, diamond heat sinks reduced chip junction temperatures by nearly 15 °C compared to conventional bonding methods, and outperformed common ceramic alternatives by even wider margins. The challenge is size: commercial polycrystalline diamond wafers top out at about 4 inches, and single-crystal wafers are smaller still, so engineers use hybrid designs that bond a diamond layer to a larger silicon substrate.
Market Size and Growth
The global industrial diamond market was valued at about $1.94 billion in 2025 and is projected to reach $3.3 billion by 2034, growing at roughly 6% per year. That growth is driven by expanding demand in construction, mining, electronics thermal management, and precision machining of advanced materials like ceramics and composites that only diamond can efficiently cut or grind.
The economics are straightforward: synthetic diamonds are cheap to produce in bulk, consistent in quality, and available in whatever grit size or shape a manufacturer needs. Natural industrial diamonds still have niche roles where their specific crystal properties matter, but they represent a tiny fraction of overall supply. For most purposes, “industrial diamond” now effectively means “synthetic diamond.”