18.36 Ct. White Opal from Madagascar

This offering from The Natural Gemstone Company is a transparent bi color ametrine presented in an emerald cut, weighing 18.36 carats, with dimensions of 17.39 x 14.24 x 10.84 mm, and a clarity grade of eye clean evaluated at eye level, with medium intense color intensity and an excellent polish. The piece originates from Madagascar and has been heat treated as a standard enhancement to stabilize and enrich the color transition between the amethyst purple and the citrine gold. The emerald cut was selected to emphasize the broad color zoning inherent to ametrine, creating large, flat facets that reveal the internal bi color contrast with clarity and precision. The cut and polish combine to produce clean facet junctions and crisp facet planes, which maximize the stone surface area that interacts with light, producing large flashes of color and a refined, glasslike sheen.

Ametrine belongs to the quartz family, and its optical properties differ from more commonly encountered gemstones such as diamond, sapphire, and topaz. Quartz typically exhibits lower refractive index and lower dispersion than those gems, which means the scintillation and fire will be softer and more subdued in strict optical terms. What differentiates this ametrine and raises its visual impact is the presence of two distinct colors in a single crystal, the exceptional size of 18.36 carats, and the eye clean clarity which allows unobstructed travel of light across the bi color interface. Compared to a single tone amethyst or citrine of similar size, this ametrine offers a dynamic interplay between purple and golden tones, appearing to change emphasis as the viewing angle or lighting shifts. Against more brilliant stones, the ametrine will not compete on dispersion driven fire, however it stands out through color drama, large reflective planes, and the unique phenomenon of two natural colors existing in a single faceted gem, qualities that are particularly prized in design work that values color narrative over optical sparkle.

For practical considerations, the emerald cut and the stone dimensions translate into a substantial visual presence suitable for a statement ring, a central pendant, or a bespoke design element in high end pieces. The eye clean clarity evaluated at normal viewing distance means the stone presents a clean face up appearance, supporting minimalist settings that expose the pavilion and allow the bi color transition to read clearly. Heat treated enhancements are commonly accepted in the trade for ametrine, and the treatment for this specimen has been applied to enhance color stability and consistency without altering the intrinsic crystal structure. The Madagascar origin is notable, Madagascar being recognized for producing ametrine material with strong, well defined zoning and attractive saturation. For customers seeking complementary accent stones we offer White Opal as an opal type that pairs well with the ametrine palette, providing soft play of light and a chalky white matrix that balances the saturated purple and golden tones of the ametrine.

In summary this 18.36 carat emerald cut bi color ametrine from The Natural Gemstone Company combines size, clarity, and a deliberate cut to showcase its natural color division, delivering a distinct aesthetic that differs from more brilliance oriented gemstones. Its appeal arises from color contrast and clarity, from the way large, polished facets present broad flashes of purple and gold, and from the rarity of such a well defined bi color presentation in a single, substantial stone. The gem suits collectors and designers who prioritize color story and presence, and for those who wish to explore paired combinations, White Opal is a considered accompaniment. For technical inquiries regarding the stone, or to discuss setting options that preserve the color transition and protect the pavilion, please contact The Natural Gemstone Company for further information.