While the average person is only familiar with diamonds in the context of jewelry, the world's hardest substance has applications well outside the world of fashion. In fact, about 80 percent of mined diamonds are unsuitable for gemstone use, according to Minerals.net. Called industrial diamonds, these gems are used to create super-durable cutting tools or abrasives, and represent the majority of the diamond trade. Industrial diamonds are not only abundant, but also in high demand. In fact, the US Geological Survey (USGS) anticipates that moving forward demand for such diamonds will only continue to rise in the US and around the world — the organization sees the expansion of infrastructure projects that require slicing through asphalt and other hard surfaces bolstering trade. However, increased demand may not result in higher prices for the diamonds. That's because industrial diamonds are often synthetic, and production techniques for the synthetic diamonds used in industrial applications are becoming less expensive. In terms of why industrial diamonds are generally synthetic, the USGS states that synthetic industrial diamonds are favored over natural industrial diamonds as their quality can be controlled, allowing organizations to tweak them to their specific needs. Indeed, in the US alone, 97 percent of industrial diamonds used are synthetic. China produces the most synthetic industrial diamonds, putting out 4 billion carats last year, as per the USGS. The US is one of the world's largest producers and consumers of industrial diamonds, and US organizations created 180 million carats of synthetic industrial diamonds in 2014. There are also several companies in the US and elsewhere that recover used industrial diamonds. In the past year, their activities yielded 38.4 million carats of secondary production.