4.18 Ct. Ametrine from Brazil

This 4.18 carat bi color ametrine from Brazil offered by The Natural Gemstone Company is presented in a classical emerald cut, with precise dimensions of 12.50 by 8.44 by 6.10 mm, a clarity grade of very very slightly included evaluated at eye level, medium intense color intensity, and an excellent polish. The emerald cut was selected to emphasize the natural color zoning inherent to ametrine, producing long step facets on the crown and pavilion that create broad, clean light windows rather than aggressive scintillation, and the cutter has oriented the color split parallel to the long axis to deliver a balanced transition between the golden citrine tones and the lilac amethyst tones. Heat treatment has been applied to stabilize and mildly intensify the color contrast, and the overall faceting proportions preserve depth and table size to maximize face up presence while minimizing windowing. At a practical level the gem presents as transparent with minimal eye visible inclusions, allowing uniform light transmission through the step facets and maintaining a crisp outline ideal for bezel or claw settings that benefit from the linear geometry of the emerald cut.

When compared to more common gem materials the brilliance and optical character of this ametrine differ in predictable but compelling ways. As a variety of quartz it has a refractive index lower than gemstones such as diamond and topaz, therefore it exhibits less high order fire and less intense scintillation than a brilliant cut diamond, and it produces broader flashes rather than pinpoint sparkle due to the step faceting. Against aquamarine and citrine which share similar optical constants, the ametrine stands out because of the permanent juxtaposition of two distinct hues within one crystal, creating contrast and visual depth that single tone stones cannot provide. The emerald cut amplifies that contrast, so the apparent brightness arises from the interplay of warm yellow gold and cool violet zones, rather than from higher dispersion. The result is a gemstone that reads as sophisticated and modern, offering distinctive color dynamics, reliable durability for everyday wear, and a measured, architectural brilliance that appeals to buyers who value directional light performance and finely executed craftsmanship.