12.39 Ct. Ametrine from Bolivia

This listing from The Natural Gemstone Company presents a remarkable transparent 12.39 carat emerald cut shape bi color ametrine, with dimensions of 14.74 x 12.93 x 9.41 mm, that demonstrates both collector grade proportions and lapidary precision. The stone is an emerald cut, producing clean step facets and a broad table that showcases the stone at every viewing angle. Clarity is graded as eye clean, evaluated at eye level, meaning that under normal unaided inspection no inclusions interfere with the visual enjoyment or optical performance. Color intensity is described as medium intense, and the polish has been evaluated as excellent, delivering sharp facet junctions and crisp facet reflections. Enhancement is disclosed as heat treated, a common and stable treatment for quartz group gems that harmonizes tone and improves color distribution without compromising the integrity of the crystal. The origin is Bolivia, the historic source of the finest natural ametrine material, which contributes provenance and desirability for an educated buyer who values traceable supply and regional gem characteristics.

The bi color nature of this ametrine is its defining feature, with balanced zones of golden citrine yellow and violet to purple amethyst color that are naturally intergrown within the same crystal. In contrast to single color amethyst or citrine, bi color ametrine offers dynamic color contrast that shifts subtly with orientation and lighting, a property that is accentuated by the emerald cut. The step facets of the emerald cut tend to emphasize color fields and create broad flashes rather than high dispersion fire, which suits a gem whose primary appeal is its dual color phenomenon. In terms of brilliance, ametrine is quartz with a refractive index in a narrow range around 1.54 to 1.55, and a vitreous luster, so its overall light return and scintillation are inherently different from higher refractive index gems such as diamond, sapphire, or spinel. What ametrine lacks in dispersion it gains in color drama and clarity windowing, and an eye clean specimen of this size produces a luminous, saturated appearance that often reads as larger to the eye than its carat weight alone would suggest. The excellent polish and large table optimize internal reflections and color zoning visibility, resulting in a visual performance that stands apart from more common single tone gemstones.

For the educated buyer, value is determined by a combination of rarity, quality, and provenance, and this Bolivian ametrine performs strongly on each of these metrics. A transparent, eye clean specimen at 12.39 carats in an emerald cut shape and excellent polish is uncommon, and the medium intense bi color saturation is well suited for both museum style settings and wearable fine jewelry. Heat treatment has been disclosed, which preserves ethical and market transparency and aligns with standard trade practices for quartz group gemstones. Practical considerations also favor ametrine, with a Mohs hardness around 7, making it suitable for a wide variety of settings with normal day to day wear when proper care is observed. Investment wise, the combination of size, eye clean clarity, and attractive color zoning from a Bolivian origin can command premium interest from collectors and designers looking for distinctive center stones. If you appreciate a gem that offers a marriage of technical lapidary excellence and natural dual color spectacle, this 12.39 carat emerald cut bi color ametrine from The Natural Gemstone Company is a compelling option that blends scientific grading criteria with the rare visual appeal unique to ametrine.