18.52 Ct. Bi Color Ametrine from Brazil

This 18.52 carat, transparent, emerald cut bi color ametrine measures 16.05 x 14.37 x 10.31 mm, and exhibits intense color intensity, very slightly included clarity evaluated at eye level, and an excellent polish. The emerald cut here is executed as a long step cut with broad table and well defined step facets on both crown and pavilion, an approach that emphasizes color zoning and internal clarity rather than brilliant scintillation. The cutter has oriented the feathered step planes to follow the natural dichroism between amethyst and citrine zones, producing a crisp, linear interface that reads as a true bi color band when viewed from the table. Heat treated to stabilize and intensify the warm golden citrine hue, this stone retains the rich purple saturation of the amethyst portion while avoiding washed out tones, and the very slightly included clarity means minor pinpoint or needle inclusions are present but do not detract from transparency or the stone's optical performance. The excellent polish and precise facet junctions deliver clean reflections and strong internal contrasts, and at this scale the stone offers a commanding presence with controlled windowing and a pronounced step interaction under directional light.

Compared to historically celebrated gems this ametrine shares the compositional drama of the famed Anahi ametrines that captured royal attention for their natural two tone contrast, while the step cut language evokes the restrained elegance of historic emerald cut jewels that were prized for clarity and table dominated color presentation. Unlike singular tone gems whose value rests on uniform saturation, the unique value of this Brazilian ametrine lies in its dual personality, the ability to exhibit two distinct color fields within a single calibrated stone, and the technical skill demonstrated in orienting facets to preserve that contrast. For collectors and designers seeking a statement center stone that balances lapidary precision with optical complexity, this piece represents a rare confluence of scale, cut, and color, and The Natural Gemstone Company presents it with full disclosure of origin Brazil and enhancement heat treated, making it an excellent candidate for bespoke high end settings or a curated gemstone collection.