Rosser Reeves Star Ruby — The Smithsonian's 138.7-Carat Burmese Cabochon
Rosser Reeves Star Ruby — The Smithsonian's 138.7-Carat Burmese Cabochon
One of the largest and finest star rubies on public display, donated to the Smithsonian in 1965
The Rosser Reeves Star Ruby is a 138.7-carat cabochon-cut Burmese ruby on permanent display in the National Museum of Natural History at the Smithsonian Institution in Washington, D.C. The stone is named for the American advertising executive Rosser Reeves, who acquired it in the early 1950s and donated it to the Smithsonian in 1965, where it remains a centrepiece of the museum's coloured-stone collection. The piece is renowned for its size, the saturation of its red body colour, and the sharpness and centring of its six-rayed star — a combination of qualities that ranks it among the finest star rubies in any public collection.
Description
The cabochon is oval in plan view, with a domed top profile cut to optimise the asterism, and weighs 138.7 carats. Body colour is a saturated medium-tone red consistent with the classic pigeon's blood palette associated with the historic Burmese Mogok deposits, although the stone's translucency — a feature of star ruby specifically — produces a slightly softer visual effect than would be seen in a faceted ruby of the same colour. The asterism takes the form of a six-rayed star, sharply defined and well-centred under direct overhead lighting, with each ray of the star running cleanly from one edge of the cabochon across the dome to the opposite edge.
The star arises from oriented inclusions of rutile silk — fine, needle-like crystals of titanium dioxide oriented along the three crystallographic directions perpendicular to the c-axis of the corundum host. Light incident on the dome of the cabochon scatters from these silk needles and concentrates into a six-rayed reflection pattern; the cutting orientation places the c-axis perpendicular to the cabochon base so that the star floats centrally on the dome. The Rosser Reeves stone is unusual in the strength and definition of its star, which is visible across a broad range of lighting conditions rather than only under sharply directional light.
Origin and treatment
The Rosser Reeves Star Ruby is documented as Burmese in origin, with the Mogok Stone Tract of upper Burma the historical source of fine star rubies of this size and quality. The Mogok deposits have been exploited for gem corundum for at least seven centuries and have produced the great majority of historically significant fine rubies and star rubies. Specific mine attribution within Mogok is generally not possible for stones of this vintage; the Smithsonian documentation describes the origin as Burmese without finer specification.
The stone is reported as untreated. Heat treatment of star ruby is gemmologically counterproductive — heating dissolves the rutile silk that produces the star — so star rubies that retain strong asterism are by definition unheated. The Rosser Reeves Star Ruby's documentation as a natural, untreated star ruby of fine Burmese origin is one of the principal contributors to its standing.
Provenance
Rosser Reeves was a Madison Avenue advertising executive, chairman of the Ted Bates agency, and an important figure in mid-twentieth-century American advertising practice. He was an avid gem collector and acquired the star ruby — then unnamed — through the international coloured-stone trade in the early 1950s. Reeves carried the stone with him as a personal talisman and sometimes referred to it as my baby; his decision to donate it to the Smithsonian in 1965 placed the gem in permanent public custody and gave it the name by which it is now known.
The Rosser Reeves Star Ruby joined a Smithsonian gem collection that already included the Hope Diamond, the Logan Sapphire, and the Star of Asia (a 330-carat star sapphire, also Burmese). The four stones together constitute one of the most significant publicly displayed gem collections in the world.
In context
Star rubies of comparable size and quality to the Rosser Reeves are extraordinarily rare. The De Long Star Ruby (100.32 carats, American Museum of Natural History, New York), the Edith Haggin de Long Star Ruby, and a small number of historically documented Burmese stones in private and royal collections constitute most of the comparable cohort. Above 100 carats with strong asterism, fine colour, and untreated status, star rubies enter a category counted in single digits worldwide.