0.40 Ct. Blue Sapphire from Ceylon (Sri Lanka)

One beautiful transparent 0.40 carat round blue sapphire is presented by The Natural Sapphire Company, with precise dimensions of 4.08 x 4.12 x 2.99 mm. This stone is fashioned in a mixed brilliant cut, combining the scintillating crown facets of a brilliant style with a well proportioned pavilion that channels light efficiently. The clarity grade is very slightly included, evaluated at eye level, which means that the stone displays only minor natural features that do not detract from its overall visual performance when set or viewed without magnification. The color is described as medium intense, a hue that is particularly prized from Ceylon Sri Lanka material for its lively blue tone that balances saturation and brightness. The sapphire has been heat treated, a stable and widely accepted enhancement that intensifies color and can improve apparent clarity, and the finish is noted as excellent polish, reflecting the careful lapidary work invested in this gem.

Understanding why this sapphire seems to sparkle so much more than many other gems requires a short look at its physical structure and how cutting choices harness that structure. Sapphires are varieties of corundum, aluminum oxide with trace chromophore elements that in this case create blue color. Corundum crystallizes in a trigonal crystal system, and that atomic arrangement gives the material a relatively high refractive index, which governs how strongly light bends as it enters and exits the gem. This sapphire benefits from that high refractive index along with modest dispersion and low to moderate birefringence, a combination that produces bright return of white light and coloured flashes without excessive light leakage. When a cutter employs a mixed brilliant design, the crown facets are optimized to break incoming light into many small flashes, while the pavilion facets are angled to return that light to the eye. The result is persistent brilliance and lively scintillation, where the interplay of small bright flashes and darker contrasts appears dynamic with every movement. Excellent polish further sharpens facet junctions, allowing crisp reflectivity and maximizing the visual impact of the stone.

From the perspective of an educated buyer this sapphire offers a number of attractive, verifiable qualities. The very slightly included clarity grade, determined by eye level inspection, confirms that inclusions are minor and natural, often acting as fingerprints of origin rather than detractors, and in many cases these internal features can be useful in distinguishing natural Ceylon material from other sources. The medium intense blue that this stone exhibits is characteristic of noteworthy Sri Lankan sapphires, which historically range from delicate cornflower blue to richer tones, and the color level here reads as versatile and wearable for both classic and contemporary jewelry. Heat treatment is disclosed, and it is important to note that heat only treatment is stable over time under normal wearing conditions, unlike some other treatments that require special handling. The mixed brilliant cut paired with the stone size of 0.40 carat creates an elegant balance, making this sapphire ideal for a refined solitaire, a delicate three stone design, or as a focal point in a bespoke piece. Because of the combination of origin, cut quality, polish, and natural clarity, the gem represents a logical purchase for a collector or client seeking long term value and consistent visual performance.

The Natural Sapphire Company stands ready to support buyers with further information, including independent gemological reports if required, guidance on setting choices that maximize light return, and advice on caring for a heat treated sapphire. For daily wear, gentle cleaning with warm soapy water and a soft brush is effective, and because heat treated corundum is generally durable, routine ultrasonic cleaning is often acceptable, though clients should inform service providers of any prior treatments before subjecting the gem to professional cleaning. For setting recommendations, an open prong or bezel that allows light to enter the pavilion is advantageous to preserve and emphasize the stone s natural brilliance, and a white metal halo can increase apparent size and contrast without muting the medium intense blue. Finally, The Natural Sapphire Company can assist with custom mounting, matching stones for pairings, and documentation for insurance appraisal, ensuring that an informed buyer receives full transparency and support. This 0.40 carat round mixed brilliant Ceylon sapphire combines the inherent optical strengths of corundum with considered cutting and finishing, delivering a sparkle and presence that reward both the eye and the discerning collector.