A $21.5M Sotheby’s Sale Just Happened

On Tuesday night in Geneva, a 10.03-carat Fancy Vivid Blue diamond - named The Mediterranean Blue - sold for CHF 17.9 million (USD $21.5 million) during a high jewellery auction, capping off a total sale of CHF 42 million, with 97% of lots sold. Damn.

The diamond was purchased by a private American collector after a brief but competitive bidding war that lasted three minutes.

Let’s break this down.

 

Source: USA Today

What Exactly Is “Fancy Vivid Blue”?

In the world of colored diamonds, blue is rare. Fancy Vivid Blue is the top tier of colour grading - a level only achieved when the saturation and tone of the stone are intense, balanced, and deeply pure.

Less than 0.1% of all diamonds mined have any trace of blue. And of those, only a small fraction meet the criteria for “Fancy Vivid.” In short, this is one of the rarest types of diamonds in existence.

Add the fact that this particular stone weighs 10.03 carats, and it becomes clear why it drew global interest.

The Price: $21.5 Million

While headlines tend to emphasise the final figure, that number reflects a few hard factors:

• Colour: Graded Fancy Vivid - nothing higher.
  
  

• Weight: 10.03 carats is significant. Most blue diamonds seen at auction are under 5.
  
  

• Clarity: The Mediterranean Blue is clean enough to meet high collector standards.
  
  

• Cut and presentation: Precise work, as expected at this level.
  
  

• Market conditions: Strong. There’s a clear appetite for top-tier stones even in a cautious economy.
  
  

Compared to other famous blue diamonds, this was fairly priced:

• Blue Moon of Josephine (12.03 ct, Fancy Vivid): sold for $48.4M in 2015.
  
  

• Oppenheimer Blue (14.62 ct, Fancy Vivid): sold for $57.5M in 2016.
  
  

In that context, $21.5M for a 10-carat stone in 2024 makes sense. The price per carat works out to roughly $2.14 million, which sits comfortably within the range for stones of this type and size.

Source: USA Today

Who Bought It?

The buyer remains anonymous, as is often the case at this level. We only know it was a private collector based in the U.S.

This isn’t the kind of diamond that gets flipped on the open market. It will likely sit in a vault for a decade, maybe set into a piece of bespoke jewellery, possibly never seen again in public.

It’s a pity, but for that money, the buyer can do what they want with it.

Why Are These Stones Important?

Beyond the drama of big auctions, Fancy Vivid Blue diamonds have quietly become one of the most reliable ultra-high-end collectables. Their performance as investment pieces has outpaced many traditional assets:

• Stable appreciation: Over the past 20 years, top-grade blue diamonds have seen consistent value growth.
  
  

• Portability: Unlike property or art, a $20M diamond fits in a pocket.
  
  

• Privacy: No public records, no headlines - unless you want them.
  
  

They’ve become the go-to for UHNW individuals looking to diversify holdings in a discreet and tangible way.

Source: USA Today

The Bigger Picture: Geneva Auction Results

While the Mediterranean Blue was the clear headline, the auction itself tells an even broader story.

• CHF 42 million total sales
  
  

• 97% sell-through rate
  
  

This level of performance shows something important: there might be global uncertainty, but the high-end jewellery market doesn’t really care. Especially when it comes to rare, well-documented stones with real value.

Quality sells. Fast.

It’s unlikely we’ll see another 10+ carat Fancy Vivid Blue on the market this year. They simply don’t come up often.

This wasn’t a fluke sale. It was another data point confirming what anyone in the high jewellery business already knows: when the product is right, there’s always a buyer.

Source: USA Today

Final Thoughts

The Mediterranean Blue represents the level of scarcity, quality, and market confidence that defines the top tier of the jewellery world. And while most people will never come close to owning something like this, it does serve as a reminder:

In an age where everything is available, some things are still genuinely rare.

And rare things, when positioned correctly, never struggle to find an owner.