1.58 Ct. Alexandrite from Tanzania

This transparent 1.58 carat cushion shape alexandrite from Tanzania combines precise proportions with a mixed brilliant cut to deliver balanced light return and a pleasing face up size at 7.54 x 5.41 x 4.27 mm. Graded as very slightly included when viewed at eye level, the stone presents minimal internal features that do not distract from its color or brilliance, and the excellent polish enhances facet crispness and surface reflection. The color intensity is medium intense, and the material exhibits the classic alexandrite color change, showing green tones under fluorescent lighting and a brownish yellow shift under incandescent light, a behavior that stems from alexandrites selective absorption and chromium related chromophore. There is no enhancement, which is an important factor for advanced buyers who prioritize untreated natural material, and the Tanzanian origin situates this gem among contemporary sources known for high quality chrysoberyl specimens. Alexandrite is durable with a Mohs hardness of about 8.5 and a refractive index in the mid 1.74 to 1.76 range, giving it an adamantine to strong vitreous luster that supports daily wear in fine jewelry.

For buyers comparing reflective qualities, this alexandrite offers a distinct optical profile when measured against other gemstones in its category. Relative to other alexandrites, the mixed brilliant cut in this cushion balances scintillation and color play, producing crisp flashes of light while preserving the color change that defines the species. Compared to color change sapphires and garnets, alexandrites higher refractive index and chromium based absorption typically produce a more dramatic and sharp transition between hues, whereas sapphires may show broader, less abrupt shifts and garnets can appear more velvety. Against emeralds and other green gems, alexandrites advantage is its unique dichroic behavior and superior surface brilliance, emeralds often show strong color but less fiery reflection due to lower refractive index and inclusions. For the educated buyer the value drivers here are clear, the natural unenhanced origin, the very slightly included clarity at eye level, the excellent polish, and the reliable color change character from Tanzania, all combine to make this 1.58 carat cushion alexandrite a technically sound and aesthetically compelling choice from The Natural Gemstone Company.