4.36 Ct. Blue Sapphire from Ceylon (Sri Lanka)

This transparent 4.36 carat round blue sapphire presents a refined combination of weight and optical clarity, with dimensions of 9.85 x 9.73 x 5.40 mm and a balanced presence suited to a variety of fine jewelry settings. The stone is fashioned in a mixed brilliant cut, an approach that merges the light gathering and return characteristics of brilliant faceting on the crown with a precision pavilion layout, resulting in an engaging optical performance. Clarity grade is recorded as very slightly included evaluated at eye level, indicating that any internal characteristics are minimal and do not detract from the overall visual appeal. Color intensity is vivid, and the finishing work includes an excellent polish that accentuates facet crispness and surface smoothness. Enhancement is by controlled heat treatment, a standard and stable practice that refines hue and transparency. The sapphire is of Ceylon Sri Lanka origin, and this provenance contributes to the gem character typically sought by connoisseurs and designers. The Natural Sapphire Company presents this example as an illustration of high quality in both material and workmanship.

Geometric faceting is a defining attribute of this sapphire and it is executed to maximize the interaction between light and the gem geometry. The mixed brilliant design arranges crown facets to capture incident light across a wide aperture, funneling rays through the table and upper facets before directing them into the pavilion. The pavilion facet angles and proportions are calibrated to promote constructive internal reflection, returning light to the observer as broad white brilliance and discrete flashes of spectral dispersion. Facet junctions are executed with precision, allowing crisp light boundaries that generate contrast and controlled scintillation. The interplay of bezel facets, star facets and upper girdle facets on the crown combines with the pavilion mains and lower girdle facets to create a balanced pattern of light and dark areas when the gem is viewed in varying lighting and movement. The result of this faceting strategy is an efficient return of light and a lively face up presentation, qualities that are especially evident in stones with strong transparency and vivid color.

The vivid color intensity of this sapphire benefits from both the material itself and the facet design, producing a saturated yet transparent face up appearance. Color distribution is even across the table and towards the girdle, and the stone retains a depth of hue without becoming overly dark in typical viewing conditions. The clarity grade very slightly included evaluated at eye level signifies that inclusions are limited in size and position, and they do not interrupt the pathways of light to any appreciable degree. Because the gem is transparent and well proportioned the vivid tone is presented without notable windowing or dead areas, and the optical depth measured by standard proportions is within a range that balances brilliance with apparent size. The calculated depth percentage derived from the dimensions provided yields approximately 55 percent, a proportion that supports a pleasing face up size while still maintaining sufficient pavilion depth for strong light return. Heat treatment has been applied to enhance color uniformity and minimize zoning, a stable enhancement that is disclosed and commonly accepted in the trade for sapphires from this region.

Cut quality and finish are central to this sapphires performance, and both attributes have been addressed with attention to detail. The excellent polish minimizes surface scattering of light, preserving the intensity of facet reflections, while careful symmetry aligns facet planes to avoid light leakage and to create coherent reflection patterns. When set in jewelry, the gem will exhibit dynamic scintillation with clean flashes of white brilliance and occasional colored dispersion, a combination that draws the eye without relying on exaggerated effects. Practical recommendations for mounting include settings that allow light access to the pavilion and crown, for example prong or open bezel styles, and designs that complement a round mixed brilliant profile such as classic solitaires or modern halo configurations. Routine care involves gentle cleaning with mild soap and warm water, and avoidance of extreme thermal shock or prolonged exposure to harsh chemicals, despite the stability of standard heat treatment. The Natural Sapphire Company provides full disclosure of origin and treatment, and makes available detailed images and grading information to support informed selection. This sapphire exemplifies the synergy of natural material quality and precise faceting, delivering a balanced and enduring gemstone suitable for discerning buyers and designers.