40.62 Ct. Blue Star Sapphire from Ceylon (Sri Lanka)

This AGL certified star sapphire offered by The Natural Sapphire Company is a translucent, oval cabochon weighing 40.62 carat, with dimensions of 19.27 by 16.24 by 11.69 millimeters, origin Ceylon, Sri Lanka, no enhancement. The gem exhibits a medium color intensity that reads as a soft to medium blue under standard daylight, with even color distribution and slight color zoning visible at oblique angles. Clarity is graded very slightly included when evaluated at eye level, a designation that reflects fine silk and minute mineral inclusions that do not detract from the overall visual performance. The cut is classic cabochon, executed to present a centered six ray asterism, and the polish is graded excellent, providing a smooth, reflective dome that enhances the star effect without introducing polish haze or surface pits.

The asterism is produced by an oriented network of rutile needles, oriented parallel to the basal pinacoid, creating a strong six ray star that responds predictably to directional lighting. The star is sharp under a single point light source, exhibiting well defined, narrow ray arms that converge near the visual center of the dome, and the star movement is clean when the stone is rotated. The translucent body allows for partial light transmission, which balances internal contrast with surface reflection, making the star appear to float on top of the sapphire. The cabochon proportions are tuned to a dome height that maximizes the star without sacrificing body color, and the oval outline aids in the perception of symmetry while accommodating natural shape tendencies of the rough. The balance between needle density and translucency is well managed, preserving asterism intensity while maintaining a pleasing blue tone.

From a lapidary perspective the piece demonstrates disciplined preforming and final shaping techniques. Orientation of the rough was selected to align the rutile fiber direction with the cabochon axis, a decision that yields centralized asterism and minimizes star eccentricity. The cutter established a dome curvature that is neither excessively high nor unduly low, allowing optimal incident light capture and preventing internal reflections that can blur the star. Edge control is precise, the transition from crown to girdle is even, and the pavilion curvature is invisible from viewing angles that matter for a cabochon presentation. The excellent polish is indicative of final lap stages completed with fine abrasives and polishing agents compatible with corundum, producing a mirror like finish. The very slightly included clarity grade reflects fine silk and occasional pinpoint crystals, features that are consistent with natural Ceylon material and that contribute to the perceptible depth and character of the stone rather than diminishing its value.

For application in jewelry the 40.62 carat scale and oval cabochon profile make this star sapphire highly suitable for a prominent pendant, a statement ring with a protective bezel, or a museum quality brooch, depending on design intent. Given the cabochon geometry and the importance of directional lighting for optimum asterism display, settings that allow the stone to receive direct light from above are preferable, and a low profile bezel can both secure the stone and frame the star. The absence of enhancement is a key consideration for collectors who require untreated natural material, and the AGL certification provides laboratory verified confirmation of origin and treatment status. Routine care involves avoiding harsh abrasives and taking precautions against hard impacts, particularly along the girdle, and professional cleaning with mild detergents and a soft brush is appropriate. The Natural Sapphire Company is available to provide high resolution imagery, detailed AGL documentation, and consultation on setting options, mounting techniques, and insurance valuation, ensuring that this Ceylon star sapphire is presented and protected in a manner consistent with its quality and rarity.