It can take months or even years for a diamond to make it from a mine to becoming a piece of jewelry. After being mined in a remote region of Siberia, a diamond is taken to an ore treatment facility, where the gem is extracted from the ore.
Then, it goes to a sorting facility 200 miles away in the diamond mining town of Mirny, where the stones are sorted by size, color, and quality - both manually and via sorting machines.
Finally, the diamond goes to the polishing and cutting facility in Moscow, a journey that's a nearly six-hour flight or a drive of almost 6,000 miles.
Alrosa mostly sells rough diamonds in bulk to jewelers, but its largest diamonds are polished and sold at international auctions.
On a recent trip to Russia, I got the chance to follow the journey a diamond takes, from an open-pit mine in Siberia, to the ore enrichment factory, to sorting facilities in a diamond mining town of Mirny, to polishing facilities in Moscow.
Here's the journey of a Russian diamond, from being dug out of the frozen ground in Siberia to selling for millions at the world's biggest jewel auctions.
Russia is the world's largest producer of diamonds.
Most of Russia's diamonds are mined in the Yakutia region of Siberia by a company called Alrosa.
Alrosa operates 12 diamond mines, both underground and open-pit mines, 10 of which are in Yakutia.
Then come the excavators and trucks to haul out the soil and the kimberlite ore, which is what contains the diamonds.
It takes a truck 40 minutes to take a round trip to the bottom of the mine and back.
This is what kimberlite ore, the igneous rock that can contain diamonds, looks like.
The trucks take the kimberlite ore to a factory for the treatment process, during which the diamond are extracted. The facility is about a 10-minute drive from the mine I visited.
The ore treatment is a mostly automated process. At this factory, about 6,600 US tons of ore are processed every single day — and it's one of the smaller facilities.
Even though almost the entire process is automated, Alrosa employees keep a close eye on the process from the control room, which shakes and creaks from the machinery operating around it.
The sorting facility is in Mirny, the diamond mining town where many miners and other employees live. It's about 300 kilometers, or almost 200 miles, from the ore treatment facility.
At this facility, diamonds are sorted by size, color, and quality.
The smaller stones go into machines that sift them through holes of varying diameters, sorting them into nine different size groups.
Once they're sorted, the larger diamonds — stones that are 10.8 carats or bigger are considered "special size" diamonds — are cut, polished, and sold at international auctions like Christie's.
After the preliminary sorting in Yakutia, the diamonds are transported almost 6,000 miles — a six-hour flight — to Alrosa's facilities in Moscow for evaluation, cutting, and polishing.
Here, the first stage is evaluating the diamond.
One part of evaluation is a 3D scan of the diamond to see the potential size and shapes that will come out of it.
The next step is cutting the rough diamonds, which is done using water lasers and can take months or even years.
After being cut, the diamonds are bruted, or formed into their preliminary shapes.
And finally, in the final stage, the diamond is polished using a spinning grading wheel coated with a special paste that's made of diamond dust.
Most of the gems Alrosa sells are rough diamonds, which means the stones have not yet been cut or polished. They sell most of these unpolished diamonds in bulk for industrial use to clients with whom they have long-term contracts.
But larger diamonds, those that are 10.8 carats or bigger and are considered "special size diamonds," are sold at international auctions.
In March 2019, Alrosa held a rough diamond auction in New York City that brought in $11.8 million.