Great Mogul
Specifications
| Weight | 275.65 carats |
|---|---|
| Dimensions | 34.85 x 25.61 mm |
| Color | Colorless |
| Weight of Rough | 808.37 carats* |
| Origin | India |
| Date Found | Early 1600’s |
| Current Location | Unknown |
Details
The Great Mogul Diamond: A Legendary Gem Lost to History
A Glimpse into History
Tavernier, a French traveler and merchant, described the diamond as “an egg cut in two”, and recorded its weight as 279 9/16 carats. After converting this from Florentine to old English, and then to modern carats, the final estimated weight lands at 275.65 modern carats.
This lone mention marks the stone’s brief moment in the spotlight—after which it vanishes from recorded history. Yet, its story doesn’t end there.
The Orloff Connection: Reemergence or Rebirth?
In the early 20th century, Alexander Fersman, a renowned Russian geologist and gemologist, studied the Orloff Diamond, part of the Russian Crown Jewels. The Orloff, weighing approximately 189 carats, also bears the distinct “egg cut in two” shape. Fersman hypothesized that the Orloff may, in fact, be a cut version of the Great Mogul.
From both a gemological and historical perspective, this theory holds weight. No other known diamond fits both the description and disappearance of the Great Mogul while matching the emergence of the Orloff. Since the Great Mogul has no definitive end, and the Orloff no definitive beginning, the hypothesis that one evolved into the other seems not only plausible—but likely.
This theory firmly positions both diamonds in the timeline of famous diamonds and adds to their fascinating, and possibly intertwined, pasts.
Confusion Over Carat Weight: The 787-Carat Myth
In 1969, a Lapidary Journal article introduced confusion by referencing a 787-carat version of the stone. This appears to be a misunderstanding. Tavernier clearly identified this figure as the weight of the rough diamond, not the finished stone.
The discrepancy prompted further discussion—particularly in Ball’s appendix to Tavernier’s writings (1682), where he examined this issue extensively (pp. 331–343). Ball also theorized a possible historical link between the Great Mogul and the Koh-i-Noor diamond, another of the world’s most valuable historical diamonds.
Challenges in Reconstructing a Lost Diamond
Tavernier’s original drawing of the Great Mogul provides minimal guidance for accurate modeling. Its lack of symmetry makes it difficult to determine the exact number of primary facets per row—12, 16, 24, 32, or otherwise.
Overlay of FemCad model (black) on Tavernier’s drawing (red)
Despite this, Scott created a detailed replica using 3D modelling software (GemCad), estimating 32 facets around the girdle and ensuring the side angles match those in Tavernier’s sketch.
Key Observations
- The overlay of the model and drawing reveals angular discrepancies, especially on the lower left and right—possibly due to misalignment during the original cutting.
- The facet pattern includes triangular and trapezoidal shapes, closely mimicking the historical sketch.
- The replica achieved 16-fold symmetry, necessary to match the visual geometry of the original.
A Brilliant Legacy
Whether or not the replica is 100% accurate, the modeled version is brilliant and scintillating, boasting an astonishing 280 facets.
The Great Mogul Diamond remains one of the most legendary diamonds in world history, steeped in mystery, speculation, and historical intrigue. Whether it lives on in the Orloff, disappeared forever, or became part of another ancient diamond with royal significance, its legacy is firmly embedded in the lore of the world’s most famous jewels.