6.17 Ct. Chrysoberyl from Tanzania

This yellowish green chrysoberyl began its story in Tanzania, recovered from artisanal alluvial pockets that concentrate well formed crystals from weathered pegmatites and metamorphic host rocks. From the moment the rough was extracted, priority was given to preserving crystal integrity and orientation, with experienced sorters identifying pieces with transparent body color and minimal alteration. The selected rough for this 6.17 carat gem showed a clean window of color and a compact crystal habit that promised an efficient yield when rationalized against the crystal axes. Careful evaluation under standard lighting and 10 power loupe inspection guided the decision to maintain as much weight as possible while choosing a cut that would maximize light return and color saturation. The gem was then submitted to a cutting program that emphasizes preservation of optical performance for chrysoberyl, a species with a refractive index range approximately 1.746 to 1.755 and a hardness of 8.5 on the Mohs scale, properties that demand disciplined cutting geometry to balance brilliance, durability, and color.

The cutter elected a mixed brilliant scheme for the oval outline, combining a modified brilliant crown with a restrained step pavilion in order to exploit chrysoberyl s refractive geometry and to produce lively scintillation without inducing a windowed centre. The finished dimensions 11.92 by 9.14 by 7.11 mm yield a length to width ratio of about 1.30, an elegant proportion for an oval that reads balanced on the finger and in a bezel or prong setting. The mixed brilliant cut preserves a well defined table and crown facet structure that disperses light into small flashes across the surface, while the stepped pavilion facets control internal reflection and provide depth to the medium intense color. Facet junctions were executed with tight symmetry and an excellent polish was achieved using progressively finer diamond laps and a final oxide lap, producing crisp facet planes and mirror like facet facets that accentuate both lustre and internal contrast. The cutter optimized crown and pavilion relationships to the known refractive indices for chrysoberyl, reducing light leakage and enhancing the stone s apparent saturation without artificial enhancement.

In hand the gem is transparent with a clarity grade of very slightly included at eye level, inclusions that are minor, localized, and do not detract from the gem s overall transparency or structural integrity. These inclusions act as natural fingerprints, confirming the gem s untreated origin, and they remain invisible in many viewing angles thanks to the faceting geometry. The color reads as yellowish green with medium intense saturation, a tonal and chromatic balance that is versatile for both modern and classic settings. There has been no enhancement, no heating, and no diffusion, a statement the knowledgeable buyer will appreciate in valuing long term rarity and stability. For practical wear the gem benefits from chrysoberyl s inherent durability, and the proportions and pavilion depth make it especially suitable for ring work where the stone will retain lively performance in everyday light. The Natural Gemstone Company stands behind the provenance and craftsmanship of this parcel, offering a transparent chain of custody from Tanzanian sourcing through precision cutting and final quality control, an assurance for collectors and connoisseurs seeking a technical and aesthetic gem that exemplifies material integrity and cutting discipline.