0.72 Ct. Blue Sapphire from Ceylon (Sri Lanka)

This transparent blue sapphire offered by The Natural Sapphire Company is a finely balanced example of natural corundum, weighing zero point seven two carats, and presented in an elegant oval outline. The exact dimensions are six point one eight millimeters by four point nine one millimeters by three point one one millimeters, and the cutting style is faceted with a mixed brilliant scheme. Clarity has been evaluated at eye level as eye clean, and the color shows an intense saturation that sits squarely in the desirable range for classic Ceylon blue. The polish is excellent, and importantly this stone has received no enhancement, retaining its natural optical character and provenance from Ceylon Sri Lanka, which contributes to both its market desirability and its geological story.

The formation of this sapphire began millions of years ago deep within the tectonic crucible of what is now Sri Lanka, where proto continental fragments and island arcs collided, producing high grade metamorphism and fluid fluxes that mobilized aluminum and trace elements. As aluminum oxide Al2O3 became concentrated in silica poor horizons and within carbonate lenses, crystal growth proceeded under high temperature and pressure conditions favorable to corundum formation. Trace concentrations of iron and titanium facilitated intervalence charge transfer that yields the blue hue, while small variations in chromium and vanadium can introduce violet to blue modifiers. Over geologic time the primary corundum crystals were liberated from their metamorphic host rocks by uplift and weathering, and they were concentrated into alluvial deposits through fluvial sorting, where the denser, gem quality crystals resisted abrasion and were ultimately recovered by skilled miners.

The cutter has translated the rough crystal habit into an oval mixed brilliant, a faceting strategy designed to harmonize color saturation with maximum light return. In this stone the crown facets are sized to preserve intense color without creating a dead window, while the pavilion presents a faceting pattern that redirects light to the table and back through the crown, enhancing apparent depth and scintillation. The mixed brilliant approach combines step elements with brilliant pavilion facets, allowing precise management of contrast and flash, and the oval outline provides an elongated visual spread that increases apparent size on the finger. The proportions represented by the stated dimensions produce an efficient girdle to pavilion relationship, and the excellent polish minimizes surface scattering, thereby preserving the sharp transfer of light between facets. Because the gem is eye clean, internal light pathways are uninterrupted, enabling the cutter to focus on optical performance rather than concealment of inclusions.

From an optical and practical perspective this sapphire embodies the properties that make corundum an enduring choice for fine jewelry. Corundum has a high refractive index and notable birefringence characteristics that, when combined with the mixed brilliant faceting, yield lively contrast and well defined facet reflection. Sapphires from Ceylon are often prized for a particular balance of blue and violet tones and for a translucency that supports vivid color under a range of lighting conditions, and this specimen demonstrates those qualities with consistent saturation across the table and crown. With a hardness of nine on the Mohs scale, the stone is exceptionally durable for daily wear, and the absence of thermal or diffusion enhancement ensures long term stability of color and the integrity of the crystal lattice. At The Natural Sapphire Company we can provide detailed gemological documentation on request, and we offer custom mounting and setting services that take advantage of the gem proportions and mixed brilliant cutting strategy to maximize both visual impact and structural security. If you require additional spectral analysis, heat history investigation, or bespoke design consultation, our specialists are prepared to advise on the technical considerations that will preserve and enhance the performance of this distinguished Ceylon sapphire.