11.36 Ct. Bi Color Ametrine from Madagascar

This transparent bi color ametrine presents as an 11.36 carat, emerald cut faceted gem, with precise dimensions of 18.47 by 9.79 by 8.32 millimeters. The stone has been cut in a classical emerald style, producing long step facets that emphasize linear planes of color and produce a refined, architectural appearance. At eye level the clarity is graded eye clean, indicating there are no inclusions visible to the unaided eye, which allows light to travel through the pavilion and table with minimal interruption and contributes to a clean, uninterrupted visual field. Color intensity is described as intense, and the combination of citrine yellow and amethyst purple zones is sharply defined by the cutter to maximize the natural bicolor zoning characteristic of ametrine. The gem carries an excellent polish, delivering crisp facet junctions and a smooth table that heightens surface luster and optical contrast between the color zones. The material is heat treated, a conventional enhancement for quartz varieties to stabilize and enrich color while preserving the stone’s structural integrity.

Sourced from Madagascar, this specimen illustrates the geological individuality that distinguishes natural ametrine. Ametrine’s bicolor character results from localized variations in iron oxidation states and thermal history within a single quartz crystal during formation, and those natural growth conditions produce internal patterns and zoning that are inherently variable and non-reproducible. The emerald cut chosen for this piece intentionally aligns the step facets with the zonal boundaries to present a linear transition between the golden yellow and violet tones, allowing the wearer to appreciate the distinct, natural separation of hues as light and viewing angle change. As a quartz species, ametrine offers a practical balance of beauty and durability, with a Mohs hardness of approximately 7, making it suitable for rings, pendants, and other daily-wear jewelry if set and cared for appropriately. Standard care includes avoiding prolonged exposure to harsh chemicals and extreme heat, routine cleaning with warm soapy water and a soft brush, and secure professional setting to protect the facet edges and corners typical of an emerald cut.

When compared to lab-grown gemstones, the advantages of a natural ametrine are primarily rooted in uniqueness, natural provenance, and the inherent complexity of its formation. Lab-grown quartz can replicate uniform color and optical properties and can be manufactured with fewer visible inclusions, yet synthetic production tends to yield stones with homogeneous color distribution and recurring internal features attributable to the growth process. In contrast, a natural ametrine like this one carries a distinct geologic fingerprint, including subtle growth zoning, fluid inclusions on a microscopic scale, and asymmetric color boundaries that testify to a singular formation history. This individuality is consequential for collectors and connoisseurs who value traceable origin, geological narrative, and the scarcity that accompanies naturally occurring bicolor quartz of this size and clarity. From an investment and collectability perspective, natural stones frequently retain desirability due to their rarity and provenance, while lab-grown alternatives, although technically impressive and often more accessible in price, generally command different market positions and expectations.

The Natural Gemstone Company presents this 11.36 carat emerald cut bi color ametrine as an exemplar of natural gemology combined with precise lapidary execution. The stone’s dimensions, eye-clean clarity, intense color intensity, excellent polish, and considered emerald cut make it a versatile centerpiece for bespoke jewelry, particularly designs that benefit from linear color contrast and a refined step-cut silhouette. For customers seeking the tangible story of a gemstone’s origin, and the tactile evidence of natural formation that appears in color zoning and microscopic internal features, this natural ametrine offers qualities that lab-grown stones cannot replicate in terms of singularity and provenance. Our product documentation and origin information support informed decision making, and we are available to discuss setting options and to provide additional imagery and viewing advice to ensure the stone’s characteristics meet the specific aesthetic and technical requirements of each commission.