0.78 Ct. Bi Color Sapphire from Montana

This 0.78 carat round bi color sapphire is precisely measured at 5.42 x 5.42 x 3.61 mm, a profile that reflects deliberate material optimization and a conservatively deep pavilion. The stone is fashioned in a mixed brilliant cut, combining a traditional brilliant facet arrangement on the crown with proportioned step or modified facets on the pavilion, an approach that balances scintillation and color concentration. Measured depth to diameter yields approximately 66.6 percent, a proportion that intentionally increases path length through the crystal to intensify the medium intense color, while the round outline and even girdle allow for predictable setting in a variety of mounting styles. The table and crown facet angles have been calibrated to enhance return of light in mixed lighting, producing controlled facet contrast that serves both to reveal the bi color character and to maintain lively brilliance despite the intentional depth of the pavilion.

Clarity is graded very very slightly included evaluated at eye level, indicating that inclusions are minimal and do not materially disrupt transparency or light transmission when viewed without magnification. Under loupe examination the needle and crystal inclusions present are stable, and they act as natural light modifiers that can contribute to subtle internal light play without compromising durability. The polish is graded excellent, the facet junctions are crisp, and the pavilion symmetry is consistent with high quality cutting standards, yielding clean facet reflections and well defined star patterns when examined face up. The bi color effect in this specimen is executed with precision, showing a warm golden to olive transition across the table and crown facets, a phenomenon produced by both the inherent trace element distribution and the controlled facet architecture, which allows different crystal orientations to reveal discrete hues as the stone is rotated. Enhancement is heat treated, a standard, stable and widely accepted practice in sapphire finishing, employed here to reduce silk, stabilize hue distribution, and improve saturation while preserving natural zoning and crystal integrity.

The provenance of this sapphire from Montana is a defining attribute that adds measurable provenance value, and it informs both the aesthetic expectations and the gemological fingerprint of the stone. Montana sapphires are noted for their unique palette that ranges from soft pastel to warm earthy tones, and they often display pleochroism or color zoning patterns that are highly sought by collectors and connoisseurs. The trace element signature typical of Montana material can include iron and other transition elements that favor greenish to yellow and golden responses under light, and when combined with careful cutting and heat treatment, these elements produce the distinctive two tone appearance evident in this gem. From a market perspective, documented Montana origin differentiates this sapphire from other sources, adding narrative value, rarity perception, and a connection to the historic alluvial and bench mines of the region. At The Natural Sapphire Company we emphasize provenance, cut quality, and transparent disclosure, and this sapphire exemplifies that commitment, offering a technically refined round mixed brilliant execution, a considered depth that enhances color intensity, excellent polish and a clarity profile that maintains high transparency. This stone is well suited for a center in a bespoke ring or a finely crafted pendant, where its bi color nature and Montana origin can be showcased, and where the technical attributes of cut and finish will interact with setting design to maximize both optical performance and long term collector value.