[1][2] A large bolide impact created the 100-kilometre (62 mi) diameter crater approximately 35 million years ago during the late Eocene epoch (Priabonian stage).

It is designated by UNESCO as a Geopark, a site of special geological heritage.

[3] For decades, the Popigai impact structure has fascinated paleontologists and geologists, but the entire area was completely off limits because of the diamonds found there.

However, a major investigatory expedition was undertaken in 1997, which greatly advanced understanding of the structure.

[9] Many of the diamonds at Popigai contain crystalline lonsdaleite, an allotrope of carbon that has a hexagonal lattice.