Hope
Specifications
| Weight | 45.52 carats |
|---|---|
| Dimensions | 25.60 x 21.78 x 12.00 mm |
| Color | Fancy Dark Grayish-Blue |
| Weight of Rough | Cut from French Blue |
| Origin | French Blue |
| Date Found | Cut in the early 1800’s |
| Current Location | Smithsonian Institution, Washington, D.C. |
Details
The Hope Diamond is the world’s second-largest blue diamond and arguably one of the most famous gemstones in history. Despite its fame, the diamond’s origin is wrapped in mystery and myth. A long-standing theory suggests that the Hope is a recut version of the French Blue, a 69-carat diamond stolen during the French Revolution. This study set out to test that theory using a combination of historical documentation, computer modelling, and photomodeling techniques.
To explore the Hope’s possible ancestry, 3D models were created for three stones: The Tavernier Blue (TB), the French Blue (FB), and the Hope Diamond itself. The TB is the original 115.16-carat rough diamond purchased by Jean-Baptiste Tavernier in India in the mid-1600s. It was cut into the 68.9-carat FB by order of King Louis XIV. After the FB was stolen in 1792, it disappeared until a 45.52-carat blue diamond — the Hope — appeared in London around 1810. This led to speculation that the Hope was cut from the stolen French Blue.
To test this, digital photomodeling was used to recreate the Hope in 3D. Over 150 high-resolution photos were taken from multiple angles and processed into over 800 data points to generate a precise CAD model. This was the most accurate of the three models since it was based on the actual stone using modern tools.
The French Blue, having disappeared in the 18th century, was reconstructed from a lead cast found in 2008 in a Paris museum. This cast was sent to Antwerp to get digitally scanned from which computer modeling could recreate the stone.
Tavernier’s drawing of the Tavernier Blue
French Blue diagram derived from Golden Fleece drawing
Once all three models were created, a process of forensic geometry was used to test whether each stone could have reasonably been cut from the previous. The Hope model was nested inside the French Blue model — and it fit. Notably, the Hope fits inside the French Blue in only one orientation, with almost no room to spare. This strongly supports the theory that the Hope is a recut FB.
Even more interestingly, the Hope features two unusual pavilion facets not typical of the standard oval brilliant cut. These facets line up precisely with the FB model’s facets, suggesting they may be remnants of the original stone. This adds further support to the hypothesis that the FB was reused — not fully recut — to maximize weight retention while hiding the stone’s identity.
What about other stones that might have resulted from the FB-to-Hope recut? Modeling showed that the leftover material would have been too small to yield any significant diamonds — perhaps only fragments smaller than 0.25 carats. This rules out theories that stones like the Brunswick Blue (13.75 cts) or the Russian Stickpin (7.6 cts) are “sisters” to the Hope — they’re too large to have come from this process.
French Blue model inside the Tavernier Blue model (Modeling by Steve Attaway)
However, when modelling the Tavernier Blue into the French Blue, there was more material loss — approximately 46 carats — potentially enough to yield one or two smaller diamonds, each less than 4 carats in ideal conditions. Even this would require perfectly executed cleaving or sawing, which was unlikely in the 17th century. So while sister stones to the FB might exist, they would be very small.
To test these ideas in physical form, plastic and wax models were milled using 3D printers and CNC machines. These confirmed the nesting of the Hope within the FB, and the FB within the TB, matching what was predicted by the digital models.
Tavernier Blue, French Blue, and Hope (computer models by Steve Attaway)
Conclusion:
- The Hope Diamond could have been cut from the French Blue.
- The 3D models confirm that the Hope fits within the French Blue in only one orientation.
- Two unusual facets on the Hope may be original remnants of the French Blue.
- There is no significant leftover material from the FB-to-Hope recut — no sister stones exist.
- The TB-to-FB cutting process could have yielded at most two small diamonds, both under 4 carats.
- The Brunswick Blue and Russian Stickpin are not related to either process.
- This modeling supports the long-standing theory of the Hope being a recut French Blue, finally giving it a likely origin after more than two centuries of speculation.