The Ahmadabad Diamond is one of the most historically significant and least conclusively documented of the great Indian diamonds — a stone of exceptional size and reputed quality that passed through the hands of Mughal emperors, Persian conquerors, and European dealers before disappearing from reliable record. Named for the city of Ahmadabad (also spelled Ahmedabad) in the western Indian state of Gujarat, the diamond is associated with the vast gem wealth that flowed through that mercantile centre during the height of Mughal power. Its story is inseparable from the broader history of Indian diamond mining, the sack of Delhi by Nādir Shāh in 1739, and the dispersal of Mughal treasures that followed — a dispersal that seeded the great European collections of the eighteenth and nineteenth centuries and left scholars debating the identities of dozens of large Indian stones for generations thereafter.

Historical Context: Ahmadabad as a Gem-Trade Centre

Gujarat occupied a pivotal position in the pre-modern gem trade. The port of Surat, lying within the same administrative province, was for centuries the principal point of entry for European trading companies into the Indian subcontinent, and Ahmadabad itself was a major inland commercial city — a centre of textile manufacture, banking, and the redistribution of luxury goods including gemstones. Diamonds from the Golconda mines of the Deccan, which supplied virtually all of the world's known diamonds before the Brazilian discoveries of the 1720s, were traded northward through brokers and merchants who operated in cities such as Ahmadabad before stones of exceptional quality were presented at the Mughal court in Agra and Delhi or exported westward to Persia, the Ottoman Empire, and eventually Europe.

The Mughal emperors were among the most avid collectors of large gemstones in recorded history. The imperial treasury assembled over successive reigns — from Bābur through Aurangzeb — contained stones of extraordinary size, many of them recorded in court chronicles such as the Āʾīn-i-Akbarī of Abū al-Faḍl, though the descriptions are rarely precise enough by modern gemmological standards to permit confident identification. It is within this context that the Ahmadabad Diamond enters the historical record.

Early Descriptions and Attributed Weight

The diamond is most frequently cited in the literature of famous stones with a weight in the region of 78 to 80 carats in its polished form, though some early European accounts give figures that are difficult to reconcile with one another because of the inconsistent use of carat weights across different national systems in the seventeenth and eighteenth centuries. The French jeweller and traveller Jean-Baptiste Tavernier, whose Les Six Voyages (1676) remains the single most important primary source for large Indian diamonds of the Mughal period, visited the subcontinent on six separate journeys between 1631 and 1668 and recorded detailed observations of stones in the imperial treasury. Tavernier's accounts, while invaluable, are not without ambiguity: he sometimes described stones under names that reflected their current custodian or the city through which they had passed rather than any intrinsic characteristic, and subsequent scholars have proposed various identifications between his named stones and diamonds that later appeared in European inventories.

The Ahmadabad Diamond has been linked by some authorities to a stone described by Tavernier as being of a pale rose or yellowish colour — consistent with the characteristic tints of many Golconda diamonds — and of a form suggesting it had been cut in the Indian fashion, meaning a shallow, table-cut or rose-cut form that preserved maximum weight from the rough rather than optimising brilliance in the European sense. Indian lapidaries of the Mughal period worked under the explicit instruction of their patrons to retain carat weight above all other considerations, a practice that frequently produced stones of considerable size but modest optical performance by later European standards.

The Nādir Shāh Dispersal

The event that most plausibly accounts for the subsequent obscurity of the Ahmadabad Diamond — and of many other Mughal treasures — is the invasion of northern India by the Persian ruler Nādir Shāh in 1739. His forces sacked Delhi and carried away a quantity of wealth that contemporaries described in almost mythological terms: the Peacock Throne, the Koh-i-Noor, the great spinel known as the Timur Ruby, and an unknown number of large diamonds and other gemstones. The Mughal treasury was effectively dismembered, and the stones dispersed into Persia, from which they subsequently entered the markets of Istanbul, Amsterdam, and London through a variety of channels — sale, gift, theft, and political settlement — over the following decades.

It is during this period of dispersal that the trail of the Ahmadabad Diamond becomes most difficult to follow. Several large Indian diamonds that appeared on the European market in the mid-eighteenth century have been proposed as candidates for re-identification with stones named in earlier Mughal or Tavernier sources, and the Ahmadabad is among those whose later history is genuinely uncertain. Some researchers have suggested a connection with stones that entered the collections of the Nizam of Hyderabad or the Nawabs of Arcot, both of whom were known to have acquired portions of dispersed Mughal gem wealth, but these identifications remain speculative.

European Accounts and the Amsterdam Trade

By the early eighteenth century, Amsterdam had established itself as the pre-eminent centre for diamond cutting and trading in Europe, and a number of large Indian stones passed through the hands of Dutch and Sephardic Jewish merchants operating in that city before being sold to royal and aristocratic clients across the continent. Several auction and inventory records from this period mention large Indian diamonds by descriptive names — the city or region of origin, the name of a previous owner, or a physical characteristic — and it is possible that the Ahmadabad Diamond appears in one or more of these records under a name that has not yet been conclusively linked to it by modern scholarship.

The difficulty of identification is compounded by the practice of re-cutting. European lapidaries, working to the tastes of their clientele, frequently re-cut large Indian stones into the brilliant or briolette forms fashionable in eighteenth-century Europe. Re-cutting inevitably changed the weight and appearance of a stone, making it impossible to match it with earlier descriptions based on carat weight alone. A stone recorded at 78 carats in a Mughal inventory might appear in a European collection at 55 or 60 carats after re-cutting, with no documentary link preserved between the two records.

Relationship to Other Named Mughal Diamonds

The Ahmadabad Diamond is sometimes discussed in proximity to a group of large Mughal stones whose identities and subsequent histories are similarly contested. Among these are the Indore Pears — a pair of large pear-shaped diamonds associated with the Holkar dynasty of Indore that eventually passed through Sotheby's in 1987 — and various stones attributed to the Mughal treasury in secondary literature. The related term "78.86ct Mughal" in some catalogues may refer to a specific stone whose weight has been recorded with greater precision, possibly through a later laboratory report, but the connection between this weight and the historical Ahmadabad Diamond has not been established beyond reasonable doubt in the published gemmological literature.

What is clear is that the name "Ahmadabad" in the context of historical diamonds functions as a geographical provenance marker rather than a description of a single, continuously documented stone. Just as the name "Golconda" has come to denote a quality standard — colourless, Type IIa diamonds of exceptional transparency — rather than a specific mine or stone, "Ahmadabad" in the historical literature reflects the city's role as a node in the Mughal gem trade rather than necessarily indicating that the stone was found in or near the city itself.

Physical Characteristics and Probable Origin

To the extent that any physical description can be attributed to the Ahmadabad Diamond with confidence, the stone is generally described in secondary sources as a large, pale-coloured diamond of Indian origin — almost certainly from the Golconda region of the Deccan, which encompassed the historic mines of Kollur, Partial, and Wajrakarur, among others. Golconda diamonds are now understood by gemmologists to be predominantly Type IIa stones: chemically pure diamonds with no significant nitrogen impurities, which accounts for their characteristic colourlessness or near-colourlessness and their exceptional transparency. The finest Golconda stones exhibit what the trade describes as a "limpid" or "watery" quality — a depth and clarity of appearance that distinguishes them from diamonds of other origins.

If the Ahmadabad Diamond was indeed a Golconda stone of the size attributed to it, it would have been a remarkable specimen by any standard. Polished diamonds above 50 carats from any source are extraordinarily rare; from the Golconda mines, which ceased to be productive at the scale required for large stones by the early eighteenth century, such a stone would today be considered a world-class historical gem.

Current Status and Scholarly Assessment

The present whereabouts of the Ahmadabad Diamond — if it survives as a discrete, identifiable stone — are unknown. It does not appear in the inventories of any major public collection, nor has it been offered at auction under that name in any sale for which records are available. Three possibilities present themselves: the stone may have been re-cut at some point in its history and now exists under a different name or in a different form; it may remain in a private collection, possibly in South Asia or the Middle East, unrecognised or undisclosed; or the historical accounts may conflate two or more stones, and the "Ahmadabad Diamond" as a single entity may be partly a construction of later scholarship rather than a continuously documented gem.

Scholars working in the field of historical gemology — a discipline that draws on court chronicles, travellers' accounts, auction records, laboratory reports, and comparative physical analysis — have made considerable progress in recent decades in tracing the histories of major Indian diamonds. The work of researchers such as those associated with the Golconda Diamond Project and published in peer-reviewed gemmological literature has clarified the identities of several previously confused stones. The Ahmadabad Diamond, however, remains among those for which a definitive account has not yet been established.

Its significance lies not only in the stone itself but in what its uncertain history reveals about the broader movement of gem wealth from the Mughal world into European collections — a movement driven by conquest, commerce, and the insatiable appetite of European courts for the prestige that large, historically resonant gemstones conferred. In this sense, the Ahmadabad Diamond is as much a historical document as a gemstone: a record, however incomplete, of the interconnected worlds of Mughal India, Safavid Persia, and early modern Europe.

Further Reading

• GIA Gems & Gemology — Golconda Diamonds (Fall 2006)
• GIA Gems & Gemology — Famous Diamonds of History