When Rarity Comes at a Price
A pink diamond valued at an estimated $18 million, a ruby auction with $52 million in sales, and a Paraíba tourmaline whose price will be determined only through competitive bidding. Several recent news stories from the gemstone trade illustrate what makes exceptional stones so desirable—and how differently the market determines their value.
Featured image: the Bulgari Pink – Photo: Christie’s
Bulgari Pink
Some gemstones change hands regularly. Others disappear into private collections for generations before reappearing on the market. The so-called “Bulgari Pink” falls into the second category. For more than 70 years, this 24-karat diamond—classified as “Fancy Intense Pink”—was owned by a European family. On November 10, it will be auctioned publicly for the first time at Christie’s in Geneva. The estimate ranges from 10 to 15 million Swiss francs, equivalent to approximately 12 to 18 million U.S. dollars.
According to the family that owns it, the rough diamond was purchased in India in the 1950s. Bulgari then crafted the ring in which the emerald-cut stone remains set to this day. In addition to its size and intense color, its history and connection to the Roman jewelry house are likely to increase its appeal to collectors.
Colorless Diamonds Remain in Demand
The fact that spectacular colored diamonds attract special attention does not in any way mean that classic colorless diamonds have lost their significance. At a recent Christie’s Jewels online auction in New York, seven of the ten highest-selling pieces of jewelry were set with colorless diamonds. The auction brought in a total of $9.3 million.
Topping the list of results was a Graff ring featuring a 7.85-carat diamond with the highest color grade (D) and a clarity grade of VS1. It sold for $256,000. For colorless diamonds as well, exceptional quality, size, clarity, and cut remain decisive factors in determining value.
High Demand for High-Quality Rubies
Gemfields offers a different perspective on the market. At an auction held in Bangkok in October, the company sold rough rubies from its Montepuez mine in Mozambique for a total of $52 million. Ninety of the 99 lots offered found buyers. A total of 92,153 carats were sold.
The average price was $565 per carat, which was 102 percent higher than the price at a previous auction in February. However, this does not indicate a general price increase: the composition and quality of the lots differed. Gemfields specifically pointed to the high demand for larger rubies of particularly high quality.
Not every ruby is a rarity. However, large stones with a sought-after color, good clarity, and corresponding quality represent a significantly narrower market segment. The auction shows that such rough stones are also in demand in the professional gemstone trade.
Paraíba Tourmaline Up for Auction
An auction on the Gem Rock Auctions platform demonstrated just how differently the market assesses the value of individual gemstones. An 8.31-carat, oval-faceted Paraíba tourmaline from Mozambique was offered without a reserve price. The starting bid was just one dollar.
After 72 bids, the greenish-blue gemstone changed hands for $18,625. That amounts to about $2,240 per carat. According to the organizers, comparable high-quality stones sometimes fetch prices around $60,000.
The relatively low premium makes this case particularly interesting. Although the seller described the stone as untreated and it weighs over eight carats, the final price remained significantly below the cited comparative values. It is not possible to determine with certainty what role color, individual quality, and the auction format played in this outcome. However, this example shows that even highly sought-after gemstones do not necessarily have a fixed market price.
Diavik: The End of Diamond Mining
While auction houses and gem dealers report on exceptional stones, a news story from Canada serves as a reminder of the limited availability of natural resources.
In March 2026, regular mining operations at Rio Tinto’s Diavik diamond mine came to an end after more than two decades. In the first nine months of the year, the company’s diamond production fell by 68 percent compared with the same period last year, to approximately 1.1 million carats. The decline is primarily a result of the scheduled closure. The processing and sale of remaining diamonds are expected to continue at least through the end of 2026.
With Diavik, a major diamond deposit is being phased out of active production. This does not automatically mean rising prices. The market is also influenced by inventory levels, demand, and the supply of synthetic diamonds. However, the closure serves as a reminder that natural diamond deposits are finite.
Quality, origin, and demand determine value
The latest results reveal a market that defies simple explanations. A price in the millions for an exceptional pink diamond says little about price trends for ordinary diamonds. Similarly, a successful ruby auction does not necessarily indicate a general upward trend for all colored gemstones.
What these examples have in common is the special status of extraordinary natural products. Geological rarity is an important prerequisite for this. However, it is color, quality, size, origin, history, and, ultimately, a buyer’s willingness to pay a certain price that determine their actual market value.
And sometimes that takes several million dollars. Other times, 18,625 is enough.
Sources: Christie’s, “Christie’s Presents The Bulgari Pink” (October 2026); Rapaport, Colorless Diamonds Dominate Top 10 at Christie’s (October 18, 2026), Ruby Auction Rakes In $52M at Gemfields (October 19, 2026), Paraiba with $1 Starting Price Sells for $18,600 at Gem Rock Auction (October 18, 2026) and Rio Tinto Production Plummets as Remaining Ore Depleted (October 19, 2026); Gem Rock Auctions, original listing for the 8.314-carat Paraíba tourmaline.
