3.40 Ct. Blue Cabochon Sapphire from Tanzania

This 3.40 carat blue sapphire from Tanzania presents a technically intriguing combination of material quality and artisanal cutting, ideal for a buyer focused on specification and customization. The stone measures 9.22 x 7.22 x 5.03 millimeters in a cushion shape that has been fashioned into a sugar loaf profile, producing a high domed crown with gently sloping sides rather than traditional faceted pavilion facets. The surface exhibits an excellent polish, and clarity is graded very slightly included, evaluated at eye level, which maintains clean transmission of light while imparting natural character under magnification. Color is described as vivid in intensity, with a saturated blue that reads rich and deep at standard viewing distances, and translucency is consistent with the sugar loaf cut, allowing internal color to glow rather than display sustained facet scintillation. The sapphire has been heat treated, a stable enhancement widely accepted in trade to optimize tone and saturation, and this treatment is compatible with standard setting and care protocols.

Understanding the sugar loaf cut is essential when planning settings, because its optical behavior differs markedly from fully faceted stones. The sugar loaf profile emphasizes body color and internal depth rather than facet generated brilliance, so light interaction is dominated by subsurface diffusion and rounded surface reflections. For a bench jeweler, this means the crown height and overall depth must be respected, and the seat in the mounting needs to be sculpted to match the 5.03 millimeter thickness to prevent rocking or stress concentration. The cushion outline at 9.22 by 7.22 millimeters lends itself to asymmetry tolerant designs, so east west mounts, off center bezels, or low profile closures can be executed while preserving visual balance. The lack of a sharply defined girdle requires a tailored bezel lip or a custom prong design that can safely embrace the rounded edges, and an open gallery will maximize transmitted light, enhancing the vivid blue color, while a closed back can be specified to mute color if a darker, more saturated appearance is desired.

Customization options span traditional and contemporary settings, each exploiting different aspects of the stone. For a classic solitaire ring, a custom four claw seat with rounded prong tips and a recessed culet pocket will secure the sugar loaf form while allowing the crown to present. A bezel mount is an excellent choice to protect the domed surface, and internal cutouts or a pierced gallery can be incorporated to allow light to enter from the pavilion side, improving color transmission. For a halo design, small brilliant cut melee diamonds set in a micro pavé surrounding the cushion outline will create contrast that reads as color pop, and the construction should include a precision milled seat to maintain uniform spacing between the sugar loaf perimeter and the halo row. Pendant and earring executions benefit from low stress soldered baskets, and the stone can be cabochon set in matched pairs for drop earrings or used singly as a pendant in a bezel with an open back. Tension settings are generally not recommended due to the absence of a regular girdle plane, however custom clamping systems and channel shadowing can be engineered by our production team for avant garde designs.

From a craftsmanship perspective, accommodating this sapphire requires deliberate planning and metalwork to complement its geometry, and The Natural Sapphire Company can develop CAD prototypes and hand fabricated mockups to validate fit and optical presentation before final production. The thickness of 5.03 millimeters calls for an internal seat dimensioned to accept the crown radius without point loading, and for bezel work a burnish height that transitions smoothly to the profile of the stone is critical. If clients require a looser or tighter color presentation, options include a custom back plate in yellow gold to warm the tone, or rhodium plated white gold to emphasize contrast and perceived saturation. Routine care guidance includes avoiding thermal shock, periodic inspection of the mounting for stress at contact points, and professional cleaning, noting that heat treated sapphires are stable but may host natural inclusions that respond poorly to aggressive ultrasonic cleaning if internal fracture features are present. For bespoke commissions, matching accent sapphires, design sketches, and full documentation can be provided by The Natural Sapphire Company, and our team is available to advise on metal selection, setting technique, and protective design features to ensure the final piece is both secure and optimized to display the vivid Tanzanian blue to best effect.