1.79 Ct. Greenish Blue Sapphire from Africa

This piece is a transparent 1.79 carat, round shape, greenish blue sapphire, measuring 7.39 x 7.28 x 4.09 mm, cut in a mixed brilliant style. The mixed brilliant cut combines a traditional brilliant crown with a step or modified pavilion, the result being a balance between bright scintillation and disciplined color distribution. The color is described as intense, the polish has been graded excellent, and the clarity is very slightly included as evaluated at eye level. This sapphire has been heat treated, a standard and stable enhancement for adjusting hue and saturation. The reported origin is Africa, and the stone presents a deep, consistent tone that benefits from both the cut proportions and the polish quality.

Optical performance is determined by a combination of proportion, clarity, color saturation, and the inherent refractive and dispersive properties of corundum. With a mixed brilliant cut and accurate proportions for its dimensions, this sapphire returns light as lively flashes across the crown facets, while maintaining a collected and even face color. The very slightly included clarity grade indicates that inclusions are minimal in size and placement, and they do not significantly interrupt the primary light pathways when viewed with the unaided eye. The excellent polish produces crisp facet junctions and sharp reflections, which enhances contrast and makes the internal color appear cleaner and more saturated. Heat treatment in this case has been applied to stabilize and intensify the greenish blue hue, yielding a richer visual depth than the rough material would display untreated.

When compared with more commonly encountered gemstones, this sapphire demonstrates a distinct optical character. Against diamond, which displays greater brilliance and higher dispersion due to its higher refractive index, this sapphire should not be expected to produce the same level of fire. Instead, it offers a more intense, chromatic appeal, where color saturation and controlled flashes of light create a presence that is felt more in the depth and body of the stone than in numerous tiny spectral flashes. Compared with beryl varieties such as aquamarine or emerald, which have lower refractive indices and generally lighter color, this sapphire displays a stronger return of light and a richer, more concentrated color field. Versus spinel, with a refractive index that is slightly lower, the sapphire often exhibits marginally greater brilliance and a more substantial feel, particularly in saturated greenish blue tones. Tanzanite, while vivid and pleochroic, is softer and more fragile, making this sapphire preferable for pieces intended for everyday wear.

Beyond brilliance alone, material performance and practical considerations contribute to why this particular sapphire stands out. Corundum’s hardness provides resilience to surface wear, helping to preserve the excellent polish and facet sharpness over time, which is crucial for maintaining visual performance. The mixed brilliant cut, along with precise dimensions and a well centered table, allows the stone to demonstrate both lively scintillation at the crown and controlled depth of color through the pavilion, a combination that many buyers seek but few common gemstones achieve concurrently. The Africa origin contributes geographical context, and heat treatment disclosure aligns with standard industry practice, ensuring predictable color stability. The Natural Sapphire Company is committed to clear disclosure of these parameters, and this sapphire exemplifies the balance of aesthetic quality and practical durability that defines premium corundum material.