The diamond was so large that it obscured the face of Botswana’s president as he held it up for closer inspection on Thursday.
President Mokgweetsi Masisi grinned as he lifted the diamond, a 2,492-carat stone that is the biggest diamond unearthed in more than a century and the second-largest ever found, according to the Vancouver-based mining operator Lucara, which owns the mine where it was found.
This exceptional discovery could bring back the luster of the natural diamond mining industry, mining companies and experts say.
The diamond was discovered in the same relatively small mine in northeastern Botswana that has produced several of the largest such stones in living memory. Such gemstones typically surface as a result of volcanic activity.
“All of the stars aligned with that volcanic eruption, and the conditions were just perfect,” said Paul Zimnisky, an independent analyst in the diamond industry.
The rough diamond is large enough to fill an adult holder’s palm, and weighs more than a pound and a half, but its value is still unclear. The valuation process could take months, Mr. Zimnisky said.
Still, the diamond will likely sell in the range of tens of millions of dollars, he added. The discovery is likely to be a boost not only for the diamond industry, but also Botswana, whose economy is heavily reliant on the export of diamonds.
“The big diamonds sell the small diamonds,” Mr. Zimnisky said.
Such whopping stones are no longer once-in-a-lifetime finds thanks to evolving technology. Lucara spotted an opportunity in Botswana when it dug up large quantities of small but coarse stones that looked like “chewed glass,” said William Lamb, the company’s chief executive. It was a hint that larger diamonds were probably being crushed in the retrieval process.
“A diamond is hard and you can’t scratch it, but it’s actually very easy to break,” Mr. Lamb said.
The company has made finding larger gems its objective, pushing for higher revenues over volume, Mr. Lamb said, holding up a resin copy of one his earlier trophies: a stone about a quarter the size of his business card.
Advanced X-ray technology, along with a more refined grinding process to separate precious gems from slabs of rock, have allowed Lucara to set and break multiple records for unearthing large gems. In 2015, the company discovered a 1,109-carat diamond, and in 2019, it found a 1,758-carat black diamond. The latest discovery is its largest yet, and second only to the Cullinan diamond, the world’s largest diamond find, which was discovered in South Africa in 1905.
The Cullinan was given to the British royal family and cut into nine separate stones, some of which form part of the crown jewels.
The latest discovery will likely be sold and cut into smaller gems and become part of the collection of a luxury brand, as Lucara’s previous two large finds were.
The diamond industry has been weathering a volatile few years recently, having had to compete with such technological threats as lab-produced diamonds. For a country like Botswana, those threats are particularly acute, since diamonds account for 80 percent of the country’s exports.
The supply of lab-produced diamonds has multiplied 10 times over since 2018, according to a recent report published by consulting group BCG. Retailers have been drawn to the higher profit margins produced by manufactured rather than mined gems, while consumers are attracted by larger, clearer cuts that come at lower prices, the report said.
The Lucara mining company, though, is undeterred, and continues to dig in hopes of finding the largest diamond yet.
“We believe that we can eclipse the Cullinan,” Mr. Lamb said.