4.99 Ct. Ruby from Mozambique

This oval pinkish red ruby weighs 4.99 carats, and measures 10.89 x 8.84 x 5.79 mm. It is transparent, Other certified Red, with intense color intensity, and has been heat treated as a standard enhancement. The gem exhibits a mixed brilliant cut, and a clarity grade of included, evaluated at eye level, with an excellent polish. Origin is Mozambique, and the piece has been prepared and presented by The Natural Ruby Company. These objective attributes define the stone for gemological assessment, and establish the baseline for how it will interact with light once set into jewelry.

The optical performance of this ruby is rooted in the crystal chemistry and crystallography of corundum, aluminum oxide, which gives the gem a high refractive index, and notable pleochroism. Corundum refracts and reflects light more strongly than many common gem materials, which concentrates and returns light to the viewer as brightness. In this specimen the mixed brilliant cut takes advantage of that intrinsic refractive property by using a combination of larger pavilion facets and smaller crown facets, creating controlled internal reflections. Those reflections are modulated by pleochroism, so that as the stone or the observer moves, subtly different red and pinkish red tones emerge from the same set of facets. The result is a dynamic, lively appearance that can read as depth color, or as scintillation, depending on the viewing angle and lighting. Included clarity at eye level indicates internal features, and in ruby those inclusions often act as secondary light scatterers that increase sparkle by creating additional reflective surfaces within the stone. When combined with an excellent polish and carefully proportioned facet junctions, these internal features contribute to a complex pattern of light return that is both vibrant and characteristic of fine rubies.

The mixed brilliant facet layout in this oval encourages a balance between color saturation and light performance. Larger facets across the crown allow the intense pinkish red hue to present evenly, while the brilliant facets on the pavilion break the light into flashes of brilliance. The cutter matched pavilion depth and crown height to the stone dimensions of 10.89 x 8.84 x 5.79 mm in order to maximize the internal reflections without excessively darkening the center of the gem. The excellent polish ensures that each facet face is smooth at the microscopic level, minimizing diffuse scattering and allowing crisp, high contrast reflections. This combination of proportions and finishing is why certain rubies display what gemmologists describe as a sparkle that is distinct from the crisp white scintillation of high dispersion gems, and also distinct from the soft glow of cabochon cut stones. The sparkle here is colored, layered, and responsive, alternating between broad flashes of saturated color and pinpoint sparkle as the stone moves.

Provenance and treatment are important to the structure and enduring appearance of the ruby, and this Mozambique origin piece has been heat treated to stabilize and enhance color and clarity in a manner consistent with established gem trading practices. Heat treatment modifies minute inclusions and the distribution of trace elements at a microscopic level, which can refine the way light is absorbed and refracted inside the crystal lattice. That treatment, together with the natural corundum structure and the careful cutting executed by our lapidary team, produces a gemstone whose light performance is both intense and nuanced. For practical use the gem is well suited to a variety of mounting styles that allow light to enter and exit freely, such as a four prong or bezel with open gallery, which will preserve the stone s dynamic interplay of color and brilliance. The Natural Ruby Company documents the stone s particulars, and can provide certification and handling recommendations. Care for the ruby using warm water, mild detergent, and a soft brush, and avoid harsh ultrasonic or steam cleaning if fracture filling or significant internal features are present, to preserve the structural and optical qualities that give this ruby its unmatched sparkle.