0.67 Ct. Greenish Blue Sapphire from Ceylon (Sri Lanka)

This 0.67 carat cushion shape greenish blue sapphire from Ceylon Sri Lanka is presented by The Natural Sapphire Company, it measures 4.71 by 4.25 by 3.71 millimeters, it is transparent with a light color intensity that allows a delicate balance of green and blue tones to manifest across the table, it is cut in a mixed brilliant pattern that combines a faceted crown designed for strong white light return with a pavilion that blends step facets and lower brilliant facets to enhance scintillation, the clarity is graded very slightly included at eye level, the polish is excellent, and the stone has received no enhancement. The cushion outline, with its gently rounded corners and softly squared silhouette, increases the visual surface area relative to its weight, and the face up presence visible in the scale photographs is a direct result of careful proportions and facet layout. The combination of modest carat weight and compact millimeter dimensions makes this sapphire adaptable to a wide range of settings, while preserving the optical properties that make Ceylon material so desirable.

The exceptional sparkle of this sapphire originates in both its fundamental crystallography and the cutter decisions that translate that structure into light performance. Corundum, the mineral species of sapphire, has a high refractive index near 1.76 to 1.77 and modest dispersion, these constants mean that light entering the stone is strongly refracted and undergoes significant internal reflection, the critical angle for sapphire is approximately thirty five degrees which permits effective trapping and redirection of light when facet angles are optimized. The mixed brilliant cut in this cushion engages those physical properties deliberately, crown facets are oriented to admit and reflect broad flashes of brilliance, while the pavilion arrangement produces numerous small flashes of scintillation as light is fractured and returned through the crown, excellent polish ensures facet junctions act as near perfect mirrors, reducing light loss to surface diffusion, the stone shows natural pleochroism so that different angles emphasize slightly different wavelengths, a dynamic of green and blue that enhances perceived depth, and the very slightly included clarity allows uninterrupted light paths in most viewing directions, all of these factors operate together to produce lively brilliance and defined scintillation rather than a flat or washed appearance.

Beyond the purely optical description, provenance and treatment status materially influence how a sapphire performs under light, Ceylon Sri Lanka sapphires are noted for even color distribution and often fine crystal clarity which provide an ideal starting point for cutters who seek to maximize both color and light return, because this stone is untreated its optical behavior is native to the material rather than the result of diffusion or other interventions, this authenticity preserves the way light interacts with internal features and with facet planes. The cushion mixed brilliant configuration gives a distinctive character, it merges the broad luminous flashes associated with brilliant faceting with the depth and patterned reflections imparted by step facets, compared with a pure step cut this sapphire offers increased scintillation, compared with a pure brilliant cut it retains a pleasing depth and a more complex pattern of light play. For practical wear the corundum hardness of nine on the Mohs scale provides durability that supports everyday settings, and when set with attention to elevation and bezel or prong design the gem will maintain its optical alignment with the viewer under typical movement. At The Natural Sapphire Company we document the dimensions clarity polish and origin to provide transparency concerning why this particular stone exhibits a sparkle that is difficult to replicate, the synergy of natural corundum properties expert cutting and careful finishing is what allows this greenish blue cushion sapphire to deliver enduring brilliance and a lively scintillation that rewards both distant glances and close inspection.