12.39 Ct. Ametrine from Bolivia

This specimen from The Natural Gemstone Company is a transparent 12.39 carat ametrine, cut in a classic emerald shape, with dimensions 14.74 x 12.93 x 9.41 mm, clarity grade eye clean evaluated at eye level, intense color intensity, and an excellent polish, origin Bolivia, enhancement heat treated. The step cut emerald style exhibits broad rectangular facets on the crown and pavilion, forming a controlled light return that emphasizes the stone two tone character. Facet junctions are crisp and symmetrical, the table plane is stable and well proportioned relative to the overall dimensions, and the pavilion steps are executed to maintain even depth and avoid windowing, resulting in broad flashes along the length of the gem rather than a dispersed brilliant pattern. The precision of the cutting amplifies the ametrine pleochroism, so the golden citrine zone and the violet amethyst zone remain distinct, yet blend harmoniously at certain viewing angles to create dramatic color zoning that changes with orientation.

From a custom jewelry perspective the size and rectangular emerald silhouette make this ametrine exceptionally versatile. At 12.39 carats and nearly 15 by 13 millimeters, the stone offers a commanding tabletop for bezel, prong, or hybrid settings, and it adapts well to both high gallery ring mounts and low profile pendants. The eye clean clarity permits open setting styles so light can pass through the pavilion steps while still preserving visual purity when viewed without magnification. Because the bi color interface is directional, ring makers and designers can align the color split along the finger axis or across it to control how the two tones present in motion. For bespoke engagement rings and statement cocktail rings the emerald cut provides predictable stone retention geometry, simplifying bezel walls and prong placements while minimizing stone movement.

Technical considerations for setting include allowance for the 9.41 millimeter depth to preserve pavilion integrity, secure prong placement at the corners to protect the facet edges, and an open gallery or subtle windowing in the setting to let the step facets breathe and show their mirror like planes. Heat treatment is standard for color stabilization, and Bolivian origin confirms classic ametrine material with stable color zoning. For designers and connoisseurs seeking a large, precision cut bi color ametrine for a bespoke piece, this gem from The Natural Gemstone Company offers textbook craftsmanship, exceptional optical behavior, and the physical presence to become a signature center stone.