10.17 Ct. Ametrine from Brazil

One beautiful transparent 10.17 carat radiant shape bi color ametrine is offered by The Natural Gemstone Company, with precise dimensions of 15.94 x 11.89 x 7.80 mm. This gem features a radiant cut that balances step and brilliant faceting, producing both strong fire and a broad surface that showcases the distinctive bisected tones of amethyst and citrine. The clarity is assessed as very very slightly included at eye level, indicating exceptional transparency for a stone of this size. Color intensity is described as intense, and the surface shows an excellent polish reflecting careful lapidary work. The gem has been heat treated, a stable enhancement commonly employed to optimize color and remove undesirable tints without affecting durability. The reported origin is Brazil, which is notable because Brazilian ametrines are increasingly sought after for their combination of clean crystal growth and vibrant color zoning. Taken together, these attributes make this particular piece a standout among collector grade ametrines, both for its scale and for the clarity and saturation that remain rare in the market.

Clarity and cutting quality are essential considerations for educated buyers, and this ametrine performs at a high level on both counts. The clarity grade very very slightly included at eye level means that at typical viewing distances the stone appears essentially eye clean, with only minute internal characteristics visible under careful examination. For gemstones in the 10 carat range, inclusions become proportionally more impactful on appearance and value, so an eye clean specimen by itself represents a premium attribute. The radiant cut here has been executed to maximize light return while preserving the integrity of the color boundary between the amethyst purple and citrine golden hues. Excellent polish indicates that the pavilion and crown facets meet smoothly, reducing light leakage and enhancing brilliance, which is particularly important for quartz family gems where scintillation and contrast define visual appeal. From a gemological standpoint the combination of high clarity, skilled cutting, and deep color saturation is what elevates this ametrine beyond typical commercial examples.

Color is the defining character of any ametrine, and this piece displays intense color intensity across both color zones, making it an exceptional example of the bicolor phenomenon. Ametrine forms when differing oxidation states of iron are preserved during crystal growth, creating zones that behave as amethyst and as citrine within a single quartz crystal. While classic ametrines are often associated with Bolivian mines, Brazilian material is increasingly recognized for larger clean crystals and vibrant zoning. Finding a bi color stone of this weight and with such concentrated and balanced color is uncommon, because larger crystals often show washed out color or heavy inclusions. The radiant cut enhances the visual separation and flow between the purple and golden areas, allowing the viewer to appreciate subtle gradients and abrupt boundaries depending on the orientation. For buyers seeking a rare statement gem that reads differently in various lighting conditions, a 10.17 carat intense bi color ametrine offers both visual drama and gemstone pedigree. Its size alone places it above the majority of ametrines available to retail and trade buyers, and the combination of size, clarity, and color intensity makes it a specimen quality example for connoisseurs.

Practical considerations for purchase, setting, and care complete the profile for an informed buyer. Quartz family gems like ametrine are durable with respect to daily wear, ranking around 7 on the Mohs hardness scale, but they are still more susceptible to abrasion than corundum or diamond, so protective settings such as bezel or partial bezel are recommended for ring designs, while pendants and brooches showcase the full face of the stone with reduced risk. Heat treatment is a stable and widely accepted enhancement in the trade, and it does not compromise structural stability or long term color permanence when properly executed. We recommend obtaining a gemological report for permanent provenance and insurance purposes, and The Natural Gemstone Company can assist in facilitating independent certification and bespoke mounting. For collectors and investors who value rarity, this ametrine should be considered a high quality acquisition because of its uncommon size and intense bi color presentation. If you are seeking a singular center stone for a custom commission or a museum quality addition to a collection, this radiant 10.17 carat Brazilian ametrine is a rare opportunity, and we at The Natural Gemstone Company are available to provide further technical details, imaging, and consultation to help integrate this gem into a finished piece.