4.37 Ct. Bluish Green Sapphire from Ceylon (Sri Lanka)

This C Dunaigre certified, greenish blue, bluish green sapphire weighs 4.37 carats, with precise dimensions of 10.83 x 7.31 x 5.57 mm. Cut into a radiant shape, this gem combines a rectangular outline with trimmed corners, a faceting arrangement that merges the light performance of brilliant styles with the clean geometry of step cuts. The color registers as vivid intensity, a saturated yet balanced blend of blue and green tones that reads uniformly across the table under typical viewing conditions. Clarity has been graded as very slightly included, evaluated at eye level, meaning the inclusions do not interrupt visual performance and are readily masked by the skillful facet layout. The surface shows an excellent polish, contributing to immediate visual snap and clean facet junctions. The material has been heat treated, a widely accepted enhancement for sapphire, and the origin is Ceylon Sri Lanka, a source renowned for lively, well saturated stones. The Natural Sapphire Company is pleased to present this certified example for the connoisseur seeking a technically refined gem with traceable provenance.

The radiant cut is a deliberate choice to amplify the inherent optical strengths of this Ceylon sapphire. The pavilion and crown employ a dense brilliant facet architecture, with numerous small facets on both pavilion and crown to fragment and return light in numerous directions. These facets increase internal reflections, producing a field of scintillation rather than large flashes, which favors uniform color distribution and lively twinkling under movement. With a depth of 5.57 mm relative to the mean diameter of 9.07 mm, the proportion yields an approximately 61 percent depth to mean diameter ratio, a proportion that optimizes the balance between light return and color saturation for a sapphire of this tone. The table facet has been sized to maintain a broad window for color assessment while allowing surrounding crown facets to act as light collectors, directing incident rays into the pavilion where precisely angled pavilion facets reflect light back through the crown. The trimmed corners reduce vulnerability to chipping without compromising the facet continuity, preserving both durability and optical performance. The facet junctions are cut with tight symmetry and careful alignment, producing crisp crisp light paths, strong internal reflections, and controlled contrast that accentuates the stone s greenish blue hue rather than washing it out or creating dark areas.

Beyond the geometric considerations, the cutting strategy addresses color zoning and inclusion masking, essential for gemstones with very slightly included clarity when evaluated at eye level. The cutter oriented the pavilion and crown facets to overlap potential inclusion zones with high return facets, so that light reflected through these areas tends to brightening and color blending rather than accentuating clarity features. This approach takes advantage of the sapphire s refractive index and pleochroic tendencies, aligning facet planes to favor the most desirable color face up while allowing movement to reveal subtle shifts toward greener or bluer directions depending on light angle. The excellent polish reduces surface scattering, increasing contrast between internal reflections and the pavilion dark zones, which sharpens scintillation and enhances perceived saturation. Heat treatment, disclosed and certifed, has refined the stone s chromophore distribution and removed minor silk, and when combined with the radiant cut s light management, the result is a vivid, lively appearance with substantial depth and brilliance for a 4.37 carat sapphire.

As specialists at The Natural Sapphire Company we emphasize both the measurable and practical implications of these technical attributes. The 10.83 x 7.31 mm footprint and 61 percent depth allow this radiant sapphire to sit well in a variety of settings, from a low profile bezel that emphasizes table color to a more open head with prongs that maximizes light interaction and scintillation. For clients interested in bespoke mounting, we recommend viewing the stone under the intended lighting conditions, since the radiant cut s performance is particularly rewarding in mixed lighting with both direct and diffuse sources. The C Dunaigre certification accompanies the gemstone, documenting origin, enhancement and the professional assessment of clarity and color, and supports its value and collectability. If you require additional technical data, such as facet counts, elevated loupe imagery, or facet plane orientation diagrams for setting design, we can provide detailed documentation and custom proposals. This greenish blue, bluish green, radiant sapphire represents a finely executed interplay of cutting science and material quality, a gemstone that rewards knowledgeable buyers who value precise proportions, refined faceting, and transparent certification from a reputable house like The Natural Sapphire Company.