6.92 Ct. Ametrine from Ceylon (Sri Lanka)

This specimen is a beautifully transparent 6.92 carat pear shape bi color ametrine, with precise dimensions of 14.16 x 11.02 x 8.05 mm, finished in a mixed brilliant cut, clarity graded as very very slightly included at eye level, and an excellent polish. Origin is Ceylon Sri Lanka, enhancement by controlled heat treatment to stabilize and slightly intensify the two tone effect. The mixed brilliant cut employed here combines a brilliant style crown geometry with a faceted pavilion that emphasizes internal light return, this strategy was chosen to balance optimal brilliance with preservation of the distinct amethyst and citrine color zones. The pear outline was proportioned to maximize the linear color separation across the table while maintaining a pleasing length to width ratio, and the girdle thickness and pavilion depth were retained within gemological tolerances to ensure secure mounting potential without sacrificing face up spread. Medium intense color intensity in both zones produces a vivid purple and a warm golden yellow that read consistently under standard lighting, and the heat treatment applied is a conventional enhancement used to ensure stable, attractive saturation without affecting the natural inclusion signature that defines the stone.

The unmistakable signature of this ametrine arises from several internal features that document its natural growth history and provenance. Primary among these are planar growth banding and a sharp color boundary plane, visible under 10 times magnification as discrete zones of iron related coloration, where differential Fe oxidation states were trapped during crystallization. Intersecting the color boundary are oriented syngenetic inclusions, including very fine two phase inclusions and minute crystalline particulates, which align with crystallographic growth faces and produce directional scattering when light is introduced parallel to the line of demarcation. In addition there are narrow, healed feather like fissures and isolated negative crystal cavities, remnants of transient fluid activity during late stage growth, and these features commonly host tiny fluid inclusions that exhibit the classic liquid gas signature of natural quartz. The combined occurrence of twin lamellae like growth features and skeletal microcrystals is consistent with rapid zoned cooling in an environment where pockets of differing iron chemistry formed adjacent to one another, a characteristic observed in quality ametrines from Sri Lanka. These internal features are generally not distracting to the unaided eye, which is why the piece retains a very very slightly included grade at eye level, yet they produce a fingerprint unique to this crystal, influencing light dispersion and the way color appears to shift at different viewing angles.

From a lapidary and design perspective these inclusions are assets rather than defects, they provide an internal topography that interacts with the mixed brilliant facet architecture to create scintillation that enhances the bi color contrast. The excellent polish means facet junctions are crisp, allowing clean transitions between the violet and golden zones and preserving the strong outline necessary for prong or open bezel settings. For jewelry applications the stone performs best when oriented so the color boundary runs across the finger, this orientation leverages the pear silhouette to present both colors simultaneously in face up view, while a low profile mounting protects the pavilion and preserves light performance. Collectors and connoisseurs will appreciate the natural markers of origin and growth, and The Natural Gemstone Company certifies the stone as heat treated, Sri Lankan origin, transparent and fully described with the dimensions and weights stated. If you require additional magnified images or a detailed inclusion map for appraisal or design approval, we will supply them on request, and we can advise on setting styles that will showcase the distinctive inclusion pattern and the exceptional bi color interplay of this 6.92 carat ametrine.