It's a question that The Economist had for people born between the 1980s and the early 2000s after the tennis ball-sized Lesedi La Rona diamond failed to sell at a Sotheby's auction last week.

The Lesedi La Rona diamond. (Photo: Nils Jorgensen/REX/Shutterstock via CP)

See, the diamond was discovered by the Lucara Diamond Corp., a Vancouver-based company that found the stone in Botswana.

They tried to auction it for $92 million. But the highest bid it drew was $79 million.

The Economist said the diamond industry is struggling to sell to millennials because they're wary of "the taint of conflict and exploitation." It's an understandable concern — but one that "irks Lucara and other listed diamond miners" because they claim to "play by the rules."