1.39 Ct. Blue Sapphire from Ceylon (Sri Lanka)

This transparent 1.39 carat oval blue sapphire from Ceylon, supplied by The Natural Sapphire Company, presents exacting proportions and classic craftsmanship. The gem measures 7.83 x 5.96 x 3.54 mm, yielding a length to width ratio of approximately 1.31 and a depth of 3.54 mm which corresponds to a depth percentage of approximately 51 percent relative to the average diameter. The oval outline is well balanced, allowing the vivid blue color to distribute evenly across the table without excessive windowing. Clarity has been evaluated as very very slightly included at eye level, indicating that the stone is effectively eye clean and that inclusions do not interrupt the visual field under normal viewing conditions. The stone is unenhanced, no enhancement, which is a significant provenance detail for collectors who prioritize natural color and untreated material, and it retains the characteristic luminous tone and saturation associated with fine Ceylon material.

The gem is cut in a mixed brilliant style, a deliberate combination of brilliant facet geometry on the crown with modified pavilion faceting to control light return and color saturation. The crown facets are arranged to produce lively scintillation, generating dynamic flashes as the stone is moved, while the pavilion facets have been proportioned to maximize internal reflection and minimize leakage. The cutter has aimed for a balance between facet size and count, using smaller crown facets to enhance scintillation, and slightly elongated pavilion facets to reinforce the stone s vivid color. The polish has been graded excellent, which is immediately apparent in the crisp facet junctions and the sharpness of facet reflections. This level of polish reduces surface light scatter and contributes directly to apparent brilliance and contrast, particularly important in a saturated blue sapphire where surface quality can influence perceived depth and color intensity.

When comparing brilliance and optical performance to more commonly encountered gemstones, the differences are instructive. Diamond, with a refractive index near 2.42 and high dispersion, produces exceptional fire and contrast, which is a different expression of brilliance than a blue sapphire. Sapphire has a refractive index around 1.76, and dispersion of approximately 0.018, values that yield less spectral fire than diamond but a stronger emphasis on color intensity and deep internal contrast. Compared to blue topaz and aquamarine, which often present paler, more watery tones and higher windowing tendencies in similar cuts, this sapphire s vivid color intensity produces an impression of greater presence even at modest carat weight. The mixed brilliant cutting strategy increases scintillation and contrast, making the stone appear lively and deep at the same time. Additionally, sapphire s pleochroic nature means that the stone can display different blue tones depending on orientation, and a well executed cut will harness that pleochroism to add complexity without fragmentation of color.

From a gemological and practical perspective, this Ceylon origin sapphire offers compelling advantages. The provenance from Sri Lanka is associated with a lively cornflower to vivid blue family of color that often reads brighter in daylight, and because this stone is unheated, its vivid color carries premium rarity. Clarity at the very very slightly included grade ensures that the piece maintains transparency and brilliance, while also providing natural internal characteristics that confirm authenticity without affecting visual appeal. On a hardness scale of 9, sapphire delivers excellent durability for daily wear in rings and high use jewelry, unlike softer blue gemstones that require more cautious settings. For mounting, a setting that elevates the pavilion to allow light to enter through the girdle plane, combined with a medium to open head design, will enhance both color and scintillation. For collectors and connoisseurs seeking a naturally colored, well cut, and eye clean material, this 1.39 carat oval from The Natural Sapphire Company represents a technically refined example of Ceylon sapphire cutting and material quality, with craftsmanship and optical performance that stand apart from more common, treated, or paler blue stones.