The Hope Diamond
The Hope Diamond
A 45.52-carat Type IIb blue diamond and one of the most documented gemstones in history
The Hope Diamond is a 45.52-carat deep-blue diamond of Type IIb classification, currently housed in the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals at the Smithsonian Institution in Washington, D.C., where it has been on public display since 1958. It is among the largest deep-blue diamonds known, and its combination of colour, historical provenance, gemmological rarity, and documented chain of ownership over more than three and a half centuries makes it arguably the most studied and written-about gemstone in existence. GIA has examined the stone on multiple occasions and confirmed its exceptional optical and chemical properties, including a striking red phosphorescence under ultraviolet illumination — a phenomenon vanishingly rare even among Type IIb diamonds.
Gemmological Properties
The Hope Diamond belongs to the rare Type IIb subgroup of diamond, distinguished by the virtual absence of nitrogen impurities and the presence of trace boron atoms substituted within the crystal lattice. It is this boron that absorbs red and yellow wavelengths of visible light, producing the stone's characteristic blue body colour. GIA grades the colour as Fancy Deep Greyish Blue, a description that captures both the saturation and the slight grey modifier that distinguishes it from the purer blues of some smaller Type IIb specimens. The stone measures approximately 25.60 × 21.78 × 12.00 mm and is fashioned in a cushion antique brilliant cut with additional facets on the pavilion — a configuration consistent with the European cutting traditions of the early eighteenth century, though the stone has been recut at least once since its original Indian fashioning.
Under long-wave ultraviolet light, the Hope Diamond emits an intense red to reddish-orange phosphorescence that persists for several seconds after the UV source is removed. This behaviour is unusual even within the Type IIb category; most blue diamonds phosphoresce blue or show no phosphorescence at all. The precise mechanism behind the red emission in the Hope remains a subject of ongoing scientific interest, with research published in Gems & Gemology suggesting that specific structural defects in combination with the boron content may be responsible.
Origins and the Tavernier Blue
The earliest reliably documented chapter in the stone's history begins with the French merchant-traveller Jean-Baptiste Tavernier, who acquired a large blue diamond in India, almost certainly from the Kollur mine in the Golconda region of what is now Andhra Pradesh, during one of his six voyages to the subcontinent between 1631 and 1668. Tavernier described and illustrated the rough stone — known today as the Tavernier Blue — in his 1676 account Les Six Voyages. The stone weighed approximately 112.19 carats in its rough or early-fashioned state and was of a triangular form with one flat side, suggesting it had already been partially worked by Indian lapidaries.
In 1668, Tavernier sold the diamond to King Louis XIV of France along with a parcel of other gems. Louis XIV commissioned the court jeweller Jean Pittan to recut the stone, and by 1673 it had been fashioned into a 67.125-carat heart-shaped or triangular brilliant — a form subsequently known as the French Blue or the Blue Diamond of the Crown. It was set in gold and worn by the king on a ribbon about the neck on ceremonial occasions. Louis XV later had it remounted in a more elaborate setting for use in the Order of the Golden Fleece.
The French Revolution and Disappearance
The French Blue was among the crown jewels seized from the royal treasury at the Garde-Meuble (now the Hôtel de la Marine) in Paris during a series of thefts in September 1792, at the height of the Revolutionary period. The stone vanished entirely from documented record for more than two decades. French law at the time imposed a statutory period of twenty years on the prosecution of stolen property, and it has been widely noted by historians and gemmologists alike that the Hope Diamond reappeared in London in 1839 — just over twenty years after the theft.
The Hope Collection and Subsequent Ownership
The blue diamond surfaces in the 1839 catalogue of the gem collection of Henry Philip Hope, a London banker of Dutch descent, from whose name the stone takes its modern designation. Hope's collection was among the finest private assemblages of gems in early Victorian England. Upon his death the collection passed through several members of the Hope family, and by the 1890s the estate's financial difficulties led to protracted legal disputes over the jewels. The diamond was eventually sold out of the family in 1901.
The stone passed through a succession of owners in the early twentieth century, including the Ottoman sultan Abdulhamid II and the dealer Salomon Habib, before being acquired in 1910 by the American socialite and heiress Evalyn Walsh McLean, who wore it frequently and publicly, helping to cement its popular reputation. McLean's estate sold the diamond in 1949 to the New York jeweller Harry Winston, Inc. Winston exhibited the Hope Diamond in numerous charitable touring exhibitions across the United States throughout the 1950s before donating it to the Smithsonian Institution in November 1958. The stone was famously delivered by registered post in a plain brown parcel — insured for one million dollars.
Scientific Study and GIA Analysis
The Hope Diamond has been the subject of rigorous scientific examination on several occasions. A landmark study published in Gems & Gemology in 2010 by researchers including Jeffrey Post of the Smithsonian and John King of GIA provided the most comprehensive gemmological analysis to date, confirming the stone's Type IIb classification, documenting its phosphorescence behaviour in detail, and examining the facet geometry to reconstruct the cutting history. The research also explored the relationship between the Hope and the Tavernier Blue using computer modelling to demonstrate that the Hope's dimensions are consistent with having been cut from the French Blue, and that the French Blue in turn could have been fashioned from the Tavernier Blue — a chain of identity that had long been hypothesised but was given its most rigorous scientific support by this work.
Separate spectroscopic studies have confirmed that the boron concentration responsible for the blue colour is present at levels of parts per billion — an extraordinarily small quantity sufficient to produce the deep saturation visible to the eye. The stone is also notable for its clarity; GIA characterises it as having no significant inclusions visible to the naked eye, which is consistent with the Type IIb category, whose members tend to form under conditions that favour high clarity.
The "Curse" and Popular Culture
The Hope Diamond has been associated in popular journalism since at least the late nineteenth century with a supposed curse bringing misfortune to its owners. Gemmological and historical scholarship treats this narrative with scepticism: the misfortunes attributed to owners are selectively cited, the chain of alleged calamities does not withstand systematic scrutiny, and the story appears to have been substantially amplified by press coverage during Evalyn Walsh McLean's ownership. The stone's documented history is remarkable enough on its own terms to require no embellishment.
Current Status
The Hope Diamond remains the property of the Smithsonian Institution and is displayed in a rotating setting that allows visitors to observe the stone from multiple angles. It is periodically removed from display for scientific study and conservation assessment. The Smithsonian estimates that the stone is seen by approximately seven to eight million visitors each year, making it one of the most viewed objects in any museum collection worldwide. No credible valuation has been placed on the stone in recent decades; its combination of size, colour, provenance, and institutional significance renders conventional market appraisal essentially meaningless.