The Hooker Emerald is a 75.47-carat step-cut Colombian emerald that anchors a brooch in the National Gem Collection of the Smithsonian National Museum of Natural History in Washington, D.C. Its weight, geographical origin and unusually complete chain of ownership give it a place among the small group of Colombian emeralds whose biographies the trade can recite from memory, alongside the Patricia, the Mogul Mughal, the Chalk and the Gachalá.

Like virtually all historic emeralds of comparable size and saturation, the stone was mined in the Muzo district of present-day Boyacá, Colombia. Spanish accounts from the sixteenth and seventeenth centuries record that the finest rough leaving the Muzo and Chivor mines was shipped through Cartagena and Seville and from there into the courts of the Mughal emperors and the Ottoman sultans, who paid prices that European royalty could not match. The Hooker stone is one of the few survivors of that east-bound trade whose later movements can be documented.

Ottoman ownership and the belt buckle

By the late nineteenth century the emerald is recorded in the personal collection of Sultan Abdülhamid II of the Ottoman Empire, who reigned from 1876 to 1909. According to the Smithsonian, the stone was set as the central element of a ceremonial belt buckle, a form for which Topkapı-period jewellers reserved their largest emeralds. After Abdülhamid was deposed during the Young Turk constitutional crisis the contents of his private treasury were dispersed; pieces from this dispersal repeatedly appear in early-twentieth-century European auction catalogues and dealers' records.

Tiffany & Co. and the tiara

The buckle was acquired by Tiffany & Co. in 1911. Tiffany's gem buyer George Frederick Kunz, then at the height of his influence, removed the emerald from its Ottoman mounting and, in keeping with the taste of the day, had it reset as the centrepiece of a diamond tiara. When the tiara failed to sell, the stone was reset again as a ring. In 1950 Mrs Janet Annenberg Hooker, daughter of the publisher Moses Annenberg and a serious collector of coloured stones, bought the ring from Tiffany. She returned to Tiffany in 1955 and commissioned the present brooch design: the emerald flanked and surrounded by 109 round brilliant and 20 baguette diamonds in a platinum mount weighing approximately twenty carats of accent stones.

Donation to the Smithsonian

Mrs Hooker donated the brooch to the Smithsonian in 1977. It joined the National Gem Collection alongside the Hope Diamond and the Star of Asia sapphire, and the gallery in which the stone is displayed bears her name. The Smithsonian's published gemmological description gives a Colombian origin and notes that the emerald is exceptionally clean for its size; the typical garden of three-phase inclusions, jagged growth tubes and calcite remnants that characterises Muzo material is present but not visually disruptive at viewing distance.

What makes the stone significant

The Hooker Emerald matters for three reasons that bear on the wider trade. First, the colour and saturation place it in the band of Muzo emeralds that the market still treats as the reference point for what an old-mine Colombian stone should look like, with a slightly bluish-green hue and an even, vivid saturation that does not collapse to grey under tungsten. Second, the inclusion picture is consistent with a stone that has not been heavily clarity-enhanced; while no modern laboratory report has been published showing absence of resin or oil, the stone is generally described as displaying an unusually clean appearance for an emerald of its weight. Third, the documented passage from a Mughal-trade-era Colombian deposit through an Ottoman imperial collection into a twentieth-century American collection illustrates the route that almost every great historic emerald has taken; the difference here is that each stage of the journey was recorded.

For the working dealer the Hooker is a useful comparator. When clients ask what a fine, large old-mine Muzo emerald should look like, the photograph in the Smithsonian's catalogue is a defensible answer. The brooch remains on permanent public view in the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals.