3.11 Ct. Blue Sapphire from Ceylon (Sri Lanka)

This 3.11 carat oval blue sapphire from Ceylon is a study in precision cutting and material quality, offered by The Natural Sapphire Company. The stone measures 9.51 x 6.54 x 5.62 mm, and its mixed brilliant cut combines a brilliant style crown with a complementary pavilion configuration that balances return of light with preservation of color. Clarity is graded very slightly included when evaluated at eye level, which allows for excellent transparency and light passage through the pavilion facets. Color intensity is described as intense, and the hue sits firmly in the saturated blue range associated with fine Ceylon material. The finish is an excellent polish that produces crisp facet junctions and minimal surface diffusion, and the stone has been heat treated, a controlled enhancement that improves color saturation without compromising the corundum crystal lattice.

From an optical and gemological standpoint this sapphire demonstrates the characteristic refractive behavior of corundum, with an index of refraction approximately 1.762 to 1.770 that yields stronger facet contrast and a slightly higher brilliance than many similar gem species. The mixed brilliant cut is calibrated to exploit corundum refraction, using smaller crown facets to create tight, lively scintillation and a pavilion geometry that optimizes internal reflections. The result is a lively play between deep blue flashes and lighter electric blue highlights. Pleochroism is present in corundum and can be observed as a shift between deeper and lighter blue tones when the stone is tilted, a phenomenon that trained observers can use to assess orientation and to set the gem in a way that maximizes the most desirable hue face up.

When compared to other gemstones in the blue sapphire category, this Ceylon stone exhibits reflective qualities that are distinct. Versus classic Kashmir sapphires this stone trades the velvety softness and diffuse glow often associated with Kashmir material for a cleaner, higher contrast appearance and more pronounced facet definition. Versus Burmese material this stone shows comparable saturation but typically a slightly lighter tone when viewed in mixed lighting, owing to the Ceylon origin and the cutter s choice to favor brilliance and scintillation over full body depth. Compared to other blue gems outside the corundum family the differences are more pronounced. Spinel, with a lower index of refraction, produces softer flashes and less crisp facet delineation, resulting in a different perception of brilliance. Tanzanite, with its strong pleochroism and lower refractive index, emphasizes color shift over facet driven scintillation. Blue topaz, though often brilliant in its own right, lacks the same refraction index and toughness of sapphire, and therefore presents a different balance of sparkle and durability.

From a craftsmanship perspective the mixed brilliant proportions in this oval have been executed to control table size and pavilion depth so that the intense color remains face up while preserving lively return. The cutter has maintained symmetrical facet arrays across the crown and pavilion, and the excellent polish minimizes light loss at the surface, increasing apparent brightness. Heat treatment applied to the sapphire is a standard, stable enhancement in corundum trade practice and is used here to remove or alter microscopic inclusions and to deepen the blue saturation. The result is a gem that performs well in mounted jewelry, retaining strong light return under both direct and diffuse lighting. For collectors and designers seeking balance between optical performance and traditional sapphire appearance, this stone from The Natural Sapphire Company presents a technically sound option, offering the hardness and resilience of corundum combined with a faceting approach that accentuates both color and brilliance.