143.33 Ct. Brown Cabochon Moonstone from Ceylon (Sri Lanka)

This exceptional 143.33 carat oval brown moonstone has been shaped as a high dome cabochon with geometric precision to optimize internal light dynamics, and the term faceting in this context refers to the deliberate geometric modeling of the cabochon profile rather than faceted planes, allowing maximum light play and a pronounced adularescence, the schiller effect that defines quality moonstone, to be presented across the broad oval table. The cutter has calibrated the dome height to a proportional ratio relative to the 42.52 by 26.89 by 16.50 millimeter dimensions, creating a symmetric crown curvature that promotes coherent internal reflection from layered feldspathic structures, and the geometry of the girdle and pavilion arcs has been tuned to minimize light leakage, concentrating the luminous phenomenon toward the viewer. Surface execution is manifest in an excellent polish, executed with progressively finer abrasives and final chemomechanical polishing to remove microabrasions, which preserves the optical clarity that supports intense color intensity, and the cabochon profile showcases the internal lamellar structure in a way that maximizes dynamic sheen when the stone is rotated or exposed to directional lighting.

From a gemological perspective this moonstone is graded very slightly included at eye level, indicating minor mineral inclusions that do not impede the overall adularescent display, and the opaque body color is a rich brown with intense saturation that frames the silvery to bluish schiller, creating depth and contrast against the polished dome. No enhancement has been applied, preserving natural surface chemistry and internal microstructure, and the provenance is Ceylon Sri Lanka, a source known for well structured feldspathic specimens with exceptional optical effects. At 143.33 carats the stone offers a commanding presence suitable for bespoke high end jewelry, where the precision of the cabochon geometry will interact with bezel or open gallery settings to accentuate light play, and mounting recommendations include low profile bezels or floating mounts to allow light ingress from the pavilion perimeter. The Natural Gemstone Company stands behind the craftsmanship with rigorous selection and cutting protocols, and this specimen exemplifies our emphasis on geometric shaping, uncompromised polish, and natural origin, making it a technical and aesthetic choice for connoisseurs seeking maximum optical performance in a single remarkable moonstone.