0.65 Ct. Blue Sapphire from Ceylon (Sri Lanka)

This cushion shape blue sapphire began its journey hundreds of millions of years ago in a dynamic tectonic environment where aluminum rich protoliths were subjected to intense heat and pressure. Deep within the crust metamorphism reconstituted existing minerals, concentrating aluminum and trace transition metals into corundum. Iron and titanium atoms became trapped in the crystal lattice, and through an intervalence charge transfer mechanism between ferrous iron and titania based centers the stone acquired its blue chromatic response. Over geologic time the corundum crystal was liberated from its host rock by erosion and migrated into Ceylonese alluvial gravels where repeated cycles of burial and exhumation rounded the crystals and polished their external surfaces. Natural thermal events and hydrothermal fluids likely annealed dislocations and modified microscopic inclusions long before human intervention. The result is a gem whose molecular structure was perfected by deep time, and whose color and clarity are legacies of both crystalline chemistry and the vigorous geological history of Sri Lanka.

The present 0.65 carat example has been precision faceted into a classic cushion outline with slightly rounded corners and balanced proportions. Measuring 5.07 by 5.02 by 3.04 millimeters it presents a carefully calibrated table and crown geometry that optimizes both scintillation and color saturation. The cutting style is mixed brilliant, where a brilliant facet arrangement on the crown combines with a controlled pavilion schema to enhance light return. Facet junctions are crisp and well proportioned, contributing to an overall symmetry that promotes even optical performance across the entire face of the gem. The crown height and pavilion depth have been matched to the refractive index of corundum in order to maximize internal reflection and minimize light leakage. The girdle has been skillfully controlled to provide sufficient thickness for secure setting, while the pavilion facets converge to a well formed culet area to preserve structural integrity. The polish is excellent, with mirror like facet surfaces that allow uninterrupted transmission and reflection of light, evidence of a high level of lapidary skill.

Color is the defining attribute of this stone, exhibiting intense saturation with a vivid blue that reads consistently in daylight and artificial viewing conditions. The vivid hue is supported by even tone distribution, with no noticeable zoning when examined under typical loupe and eye level inspection. Clarity is evaluated as very very slightly included at eye level, meaning that microscopic pinpoint and feather like inclusions are present but do not detract from transparency or brilliance when viewed without magnification. These internal characteristics attest to the natural growth environment of the crystal and in many cases contribute to the gemological certitude of origin. The sapphire has undergone heat treatment, a stable enhancement technique that is widely accepted in the trade and which refines blue saturation and reduces the visibility of silk like rutile inclusions. During controlled thermal annealing, submicroscopic inclusions can coalesce or diminish and iron valence states can be adjusted to intensify blue tones, without compromising the stone's integrity or hardness. Optical properties of corundum such as a refractive index in the range expected for blue sapphire and a vitreous luster are evident, and pleochroism is moderate with blue to slightly purplish blue facets when viewed at different angles, a trait that the cutter has taken into account when orienting the pavilion and crown axes.

Provenance is a key aspect of the narrative and this sapphire is documented as originating from Ceylon Sri Lanka, a region with a storied history of producing vibrant blue sapphires from both primary metamorphic sources and secondary alluvial deposits. The geological signature of Ceylon stones often includes a combination of high color saturation and pleasing clarity, qualities that are manifest in this 0.65 carat cushion gem. For practical considerations the gem is robust with corundum hardness at nine on the Mohs scale, making it well suited to daily wear in rings and other jewelry with appropriate protective settings. When set, the measured dimensions allow for a variety of mounting styles while the mixed brilliant cut will yield strong face up color and lively scintillation. At The Natural Sapphire Company each stone is evaluated and described with technical transparency, and this sapphire is presented with full disclosure of enhancement and origin to enable informed selection. The Lapidary choices embodied in its proportions and polish reflect both aesthetic priorities and optical engineering, delivering a piece that is scientifically grounded and visually compelling.