10.37 Ct. Bluish Green Tourmaline from Brazil

This 10.37 carat emerald cut bluish green tourmaline from Brazil presents a combination of optical precision and material quality that distinguishes it within curated collections. The stone measures 19.48 by 8.33 by 6.37 millimeters, yielding an elegant length to width ratio of approximately 2.34, which enhances the step cut silhouette and provides an elongated table plane for controlled light interaction. Cut in a classic emerald style with faceted steps, the piece is finished to an excellent polish, and evaluated at eye level as very very slightly included, meaning the gem is essentially clean to the unaided eye with minor internal characteristics only perceptible under magnification. The piece has undergone a targeted heat treatment to stabilize and intensify its bluish green hue, and this enhancement is executed to industry standards to preserve transparency and natural character. Presented by The Natural Gemstone Company, this tourmaline combines gemological integrity with artisan cutting to produce both aesthetic presence and technical excellence.

The faceting architecture of this emerald cut tourmaline is central to its exceptional sparkle and optical behavior. Step facets on the crown and pavilion form long, parallel planes that emphasize broad flashes of light rather than the small, rapid scintillation associated with brilliant cuts. With precise facet alignment and tightly matched facet junctions, the synchronized reflection pathways deliver broad luminous windows across the table and elongated flashes along the pavilion, creating a lively yet controlled play of light. Tourmaline possesses a refractive index in a range that supports strong internal reflection, and its modest birefringence contributes subtle depth without fragmenting color. The cutter balanced pavilion depth and crown angle to optimize light return for this specific size, preserving saturation in the intense color while avoiding light leakage that would mute brilliance. The excellent polish contributes to crisp facet edges and minimal surface diffusion, preserving contrast between light and dark facets which enhances perceived brilliance and scintillation when the gem is viewed in varied lighting conditions.

Craftsmanship techniques applied to this tourmaline further elevate its visual performance and structural stability. The symmetry of the emerald cut is critical for uniform light distribution across the table and along the step facets, and the cutter achieved proportional facet lengths and even facet spacing to maintain directional coherence in reflected rays. Heat treatment was applied with controlled parameters to homogenize subtle color zones typical of tourmalines and to deepen the bluish green tone without compromising clarity or creating internal stress. The girdle was finished to a consistent thickness to support setting options while minimizing unwanted light escape, and facet junctions were carefully polished to reduce microabrasion that can scatter light. The result is a gem that exhibits broad, velvety flashes of color, controlled scintillation along the step planes, and a depth of hue that reads intensely in both daylight and incandescent illumination. For collectors and designers seeking a sizable tourmaline that balances a refined cut, top grade polish, and natural character, The Natural Gemstone Company offers this gem as a standout choice for a bespoke center stone or a museum quality addition to a gemstone portfolio.