1.01 Ct. Cobalt Spinel from Tanzania

This pear shaped cobalt spinel presents as a transparent, Other certified Blue gem weighing 1.01 carat, its calibrated dimensions 7.45 x 5.39 x 3.61 mm indicate a well judged balance between length and width, and a depth proportion that measures approximately 56 percent relative to the average linear dimension. The cutting style is a mixed brilliant cut, where a faceted crown with a series of kite and star facets transitions to a brilliant pavilion optimized for light return. The cutter has established a restrained table size to preserve crown fire while permitting strong pavilion brilliance, and the overall symmetry of the pear outline is tight, with a consistent girdle thickness that will facilitate secure setting in a tube or bezel. Polish is graded excellent, the facet junctions are crisp, and the lapidary work demonstrates controlled facet tilt and alignment that reduce windowing and maximize scintillation along the length of the stone.

Color presentation is dominated by cobalt induced blue chroma, the hue registering as a pure saturated blue with an intense color intensity that reads uniformly across the crown and pavilion. As a member of the isometric spinel family, this material is isotropic and shows negligible pleochroism, therefore the blue remains stable across viewing angles and under standard lighting. The combination of intense saturation and transparent body allows for concentrated reflections from the pavilion facets, producing lively blue flashes interspersed with deeper blue zones that enhance perceived depth. Heat treatment was applied as an enhancement, selectively improving color saturation without compromising crystallographic integrity, and the resulting tone and saturation are well suited to both fine jewelry and collector grade mounts. Because the stone is free from strong dichroism and is isometric, optical behavior is dominated by facet geometry and internal clarity rather than directional absorption, which simplifies design considerations for ring or pendant settings.

Inclusions in this specimen are present at the very slightly included level when evaluated at eye level, and they function as fingerprint features that authenticate and individualize the gem. Observed internal characteristics include a scattering of minute crystal platelets and delicate needle like inclusions that align along octahedral growth directions, together with a few tiny negative crystal cavities that refract light in a manner that contributes to the jewel like scintillation when viewed through the crown. These inclusions do not materially impair transparency, rather they create internal lively points and a subtle texture that distinguishes this specific stone from others of similar size and color. From a gemological standpoint, these inclusion types are consistent with natural Tanzanian spinel formation, and when coupled with the documented heat treatment and laboratory certification, they aid provenance verification and long term identification. The Natural Gemstone Company offers this 1.01 carat pear shaped cobalt spinel as a collector grade, wearable gem, the craftsmanship and optical performance make it ideal for a classical solitaire pendant or an elegant halo ring setting, and our team can provide further technical measurements or mounting recommendations to ensure optimal light performance and durability.