1.06 Ct. Bi Color / Parti Sapphire from Ceylon (Sri Lanka)

One transparent 1.06 carat round bi color parti sapphire, dimensions 6.48 by 6.55 by 3.55 millimeters, faceted, mixed brilliant cut, clarity grade very slightly included evaluated at eye level, intense color intensity, excellent polish, enhancement heat treated, origin Ceylon Sri Lanka. The gem presents balanced proportions for a round form, with a slightly deeper pavilion that complements the mixed brilliant facet pattern. The parti color distribution alternates between a cornflower blue and a vibrant yellow green, creating distinct color zones that remain visible through rotation and changes in light. Transparency is high throughout the stone, and the very slightly included clarity grade indicates that any natural features are small and do not materially interfere with the overall visual performance when viewed without magnification. The excellent polish enhances facet definition and maintains crisp facet junctions, which is especially important for a mixed brilliant style where contrast between crown and pavilion facets determines scintillation.

When assessing brilliance and light performance, this parti sapphire differs from more common gemstones in several important ways. Sapphire has a refractive index near 1.76, higher than beryl varieties such as aquamarine and higher than topaz, which means that for comparable cuts and polish it returns more light to the eye and yields a stronger overall brilliance. By contrast diamond, with a refractive index near 2.42, produces higher light return and more pronounced dispersion or fire, which is why diamonds exhibit a different kind of brilliance. The mixed brilliant cut used on this round sapphire is designed to maximize light return from the crown while preserving pavilion depth, producing bold scintillation and lively contrast. In the case of a parti sapphire, the juxtaposition of blue and yellow green color zones increases perceived sparkle, because the eye registers quick alternations of color along with facet flashes, creating an engaging dynamic that differs from the uniform color fields of most single tone gems. Additionally, corundum can display pleochroism, a directional color response, and while pleochroism in blue parti sapphires is typically subtle, it can contribute to shifting color notes as the stone or light source moves, further enhancing visual interest beyond what is commonly seen in colorless gemstones or single tone colored stones.

Beyond optics, the material properties and finish of this sapphire contribute to its distinction. Corundum ranks nine on the Mohs hardness scale, which places it among the most durable gemstones available for daily wear, second only to diamond, and this mechanical robustness allows for a wide range of mounting options. The heat treatment reported for this stone is a conventional and stable enhancement used throughout the trade to refine color and clarity, and when performed responsibly it produces durable color saturation without compromising structural integrity. The very slightly included clarity grade means inclusions are minor and often act as natural fingerprints of origin, with many collectors and gemologists regarding them as acceptable within a transparent, intensely colored stone. Excellent polish ensures minimal light scattering at the facet surfaces, which is essential for maintaining crisp brilliance, and the mixed brilliant cutting philosophy here leverages both large crown facets and smaller pavilion facets to create a balanced interplay of flash and depth.

This sapphire is a representative example of Ceylon material that combines lively color, distinct parti zoning, and precise cutting, attributes that are documented and offered by The Natural Sapphire Company. The piece is well suited to settings that showcase its round outline and color dynamics, including open gallery mounts that permit light entry from the side, and bezel or prong styles that maintain security while allowing the stone to interact with ambient light. For customers and designers seeking a gem that provides a more complex visual experience than a uniformly colored sapphire or a softer colored beryl, this stone offers sustained interest through its dual tone palette and controlled brilliance. Documentation regarding origin, treatment, and the gemological assessment accompanies the stone, and further evaluation or bespoke setting consultation can be provided upon request.