The Maharani Cat's Eye — A 58.19-Carat Chrysoberyl in the Smithsonian Collection
The Maharani Cat's Eye — A 58.19-Carat Chrysoberyl in the Smithsonian Collection
One of the largest fine cat's-eye chrysoberyls on public display, in the National Gem Collection in Washington
The Maharani Cat's Eye is a 58.19-carat chatoyant chrysoberyl cabochon held in the National Gem Collection at the Smithsonian Institution's National Museum of Natural History in Washington, D.C. The stone is one of the largest cat's-eye chrysoberyls of demonstrably fine quality on public display anywhere in the world and a touchstone for any discussion of the species in its phenomenal variety.
The stone
The Maharani Cat's Eye weighs 58.19 carats and is cut as a high-domed cabochon, the form universally adopted for chatoyant gem material. The body colour is a warm honey to greenish-yellow, characteristic of fine Sri Lankan chrysoberyl, and the chatoyant band — the bright streak of light that crosses the dome perpendicular to the long axis of the cabochon — is sharply defined, well-centred, and visible across a wide range of viewing angles. These qualities together — strong colour, sharp band, good centring, broad rotational range — define the upper tier of cat's-eye chrysoberyl and are the criteria against which any large stone is measured.
The stone entered the Smithsonian collection as a gift to the National Gem Collection. It is displayed in the gallery alongside other phenomenal chrysoberyl, the alexandrite specimens, and the broader gallery of important coloured stones.
The chatoyancy phenomenon
Chatoyancy — the cat's-eye effect — arises from the reflection of light from oriented inclusions within the host crystal. In chrysoberyl, the inclusions are typically fine parallel needles or channels, in some cases attributable to growth tubes and in some cases to oriented mineral inclusions. When the host is cut as a cabochon with the dome perpendicular to the inclusion direction, light reflecting from the inclusions converges into a bright band that appears to float across the stone's surface.
The quality of the band depends on the density, parallelism, and fineness of the inclusions. Where the inclusions are dense and finely parallel, the band is sharp and well-defined; where they are sparse or imperfectly oriented, the band is diffuse or broken. Chrysoberyl is the species in which the cat's-eye phenomenon is most commonly seen at its finest, and the phrase cat's-eye used unqualified in the trade is conventionally taken to mean cat's-eye chrysoberyl. Other species — quartz, tourmaline, beryl — also show chatoyancy but are conventionally designated by species name (cat's-eye quartz, cat's-eye tourmaline, and so on).
Provenance and naming
Sri Lanka is the principal historical source for fine cat's-eye chrysoberyl. The alluvial deposits of the Ratnapura district have produced the bulk of the world's gem-quality chrysoberyl over the past two centuries, and the warm honey-to-greenish body colour of the Maharani stone is consistent with Sri Lankan origin. India and East Africa have produced cat's-eye chrysoberyl in smaller quantities, with some Indian material historically reaching the European trade through princely commissions.
The stone's name reflects the historical association of large cat's-eye chrysoberyls with Indian royal collections; chrysoberyl was a stone of particular significance in Indian gem culture, and large cat's-eye examples were valued ceremonial pieces. The name Maharani is a museum convention rather than a documented family provenance, and reflects the broader cultural association of the species with Indian royal jewels rather than ownership by a specific named Maharani.
The Smithsonian National Gem Collection
The National Gem Collection at the Smithsonian houses many of the most important historical and significant individual gemstones in public hands, including the Hope Diamond, the Logan Sapphire, the Carmen Lúcia Ruby, and important alexandrite, emerald, and topaz specimens. The cat's-eye chrysoberyl gallery includes several stones of substantial weight, of which the Maharani is the largest of demonstrably fine quality. The collection's published catalogue and the museum's online resources document the principal stones, their weights, and their provenance details.
In the trade
For dealers and collectors of cat's-eye chrysoberyl, the Maharani functions as an upper-end reference stone. Cabochons in the 50-carat-plus range are exceptional, and the combination of size, colour, sharp band, and centring exhibited by the Maharani is rarely matched in commercial material. Stones in the 5-to-10-carat range with comparable quality of body colour and band are achievable in the contemporary market and trade at substantial per-carat prices. Smaller stones with weaker bands or off-centre chatoyancy are common and trade at much lower prices.
Identification is straightforward under microscopy: chrysoberyl's hardness of 8.5, refractive indices of approximately 1.746 to 1.755, and characteristic inclusions distinguish it from cat's-eye quartz (lower RI, lower hardness) and from cat's-eye apatite (much lower hardness). Synthetic chrysoberyl exists but is uncommon in the gem market.