1.73 Ct. Bi Color Sapphire from Australia

This transparent 1.73 carat cushion shape bi color sapphire is presented by The Natural Sapphire Company as an exceptional choice for an engagement gemstone, combining precise proportions with a captivating color profile. The stone measures 6.66 x 6.66 x 4.68 mm, a classic cushion footprint that balances presence and wearability on a variety of ring designs. The mixed brilliant cut employed here marries a brilliant style crown with a complementary pavilion geometry, engineered to maximize light return while preserving the soft pillow silhouette inherent to the cushion form. The overall cutting approach prioritizes symmetry and optical performance, with calibrated facet junctions and a table dimension selected to enhance both face up color and internal light dynamics. Origin is Australia, and the sapphire has been heat treated, a controlled enhancement applied to stabilize and intensify the natural chromatic characteristics while maintaining the material integrity expected for daily wear.

Color is the defining attribute of this bi color sapphire, graded at intense color intensity, and it displays a distinct duality that separates it from single hue stones. The gem exhibits controlled color zoning that allows two complementary hues to coexist without appearing patchy, a result of both natural growth conditions and judicious orientation by the cutter. At face up viewing the transition between hues reads as deliberate and harmonious, providing visual interest as the stone moves under varying light conditions. The bi color nature benefits from the cushion outline and the mixed brilliant faceting which disperses light in a manner that accentuates color contrast while preserving saturation. For buyers with technical sensibilities, note that the stone demonstrates pleochroic behavior consistent with corundum, presenting slightly different color dominance when viewed along different crystallographic axes, an effect that can be exploited in setting to favor a preferred hue.

From a clarity and finish perspective this sapphire is evaluated as eye clean at normal viewing distance, indicating that no inclusions are apparent to the naked eye. Such clarity allows the faceting design to perform optimally, with internal reflections uninterrupted by significant planes or crystals. The mixed brilliant cut configuration typically employs a brilliant facet arrangement on the crown to produce scintillation and lively flashes, while the pavilion is cut to angles that control return and extinction, a balance calibrated to the stone dimensions to avoid windowing or excess darkness. The polish is graded excellent, meaning facet surfaces are free from detectable abrasion or polish lines, and facet junctions meet with precise crispness. These aspects collectively produce strong contrast and lively return, attributes that are particularly desirable in an engagement ring where the stone is observed at close quarters daily.

As an engagement gemstone this 1.73 carat cushion bi color sapphire offers both emotional resonance and technical robustness. Sapphires rank nine on the Mohs hardness scale, providing superior resistance to abrasion and suitability for continuous wear, and the heat treated enhancement applied here is a stable and widely accepted practice that enhances color permanence without compromising structural stability. The cushion shape and moderate depth make this sapphire adaptable to a range of settings, from a classic four prong solitaire that emphasizes the cushion outline to halo and three stone settings that use surrounding diamonds to amplify perceived size and to frame the bi color effect. For clients seeking precise optical control, orienting the pavilion and crown axis during mounting can emphasize a desired hue face up, a customization we can manage at The Natural Sapphire Company to ensure the engagement ring showcases the most flattering color presentation. We welcome technical inquiries regarding facet proportions, recommended setting clearance, and any bespoke mounting considerations to integrate this stone into an enduring and technically refined engagement design.