A Siberian crater holds a massive, hidden fortune of industrial-grade impact diamonds

Countries & Cities · Published 30 September 2026 Swipe more like this →

In short: Hidden in the remote reaches of northern Siberia lies the Popigai impact structure, a 100-kilometre-wide scar from a massive asteroid strike 35 million years ago. This ancient collision didn't just reshape the landscape; it instantaneously transformed graphite into a unique, ultra-hard diamond deposit that remains largely untouched today.

Formed during the late Eocene epoch, the Popigai impact structure is one of the largest verified craters on Earth. Located roughly 300 kilometres east of the Khatanga outpost, this site serves as a vital laboratory for geologists studying cratering processes. Its status as a UNESCO Geopark highlights its significance, as it is considered the best-preserved large terrestrial complex crater featuring a central-peak ring. The impact event, which may be linked to the Eocene–Oligocene extinction, likely involved a H chondrite asteroid several kilometres in diameter.

The site's most striking feature is the creation of 'impact diamonds.' When the asteroid struck, the immense shock pressure converted local graphite deposits into diamonds within a 13.6-kilometre radius of the impact point. These are not typical gemstones; they are often embedded with lonsdaleite, a hexagonal carbon allotrope that can be significantly harder than ordinary diamonds. Researchers have even identified carbon polymorphs at the site that combine diamond and lonsdaleite, resulting in material even harder than pure lonsdaleite.

Despite the immense volume of these diamonds, they remain unmined. Their remote location in Siberia, combined with a lack of necessary infrastructure, makes extraction economically unviable compared to modern synthetic diamond production. Furthermore, because these diamonds are structurally distinct and often contain specific crystalline impurities, they are generally considered unsuitable for the jewelry market. While they hold potential for specialized industrial applications, the site remains primarily a place of scientific fascination rather than a commercial mining operation.

For decades, the area was strictly off-limits due to its diamond content, but a major 1997 expedition significantly advanced our understanding of the crater's formation. Scientists continue to investigate whether Popigai formed simultaneously with other craters, such as the Chesapeake Bay and Toms Canyon structures, which also date to approximately 35 million years ago. This ongoing research helps refine our timeline of Earth's bombardment history and the geological consequences of large-scale bolide impacts.

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