6.61 Ct. Greenish Blue Aquamarine from Tanzania

One beautiful transparent 6.61 carat cushion shape greenish blue aquamarine, measuring 12.12 x 12.08 x 7.36 mm, presents a rare combination of size and classic gemstone appeal. This stone is faceted with a mixed brilliant cut, and carries a clarity grade of included, evaluated at eye level, which is typical for natural aquamarine and often acceptable to informed buyers who appreciate natural character and stability. The color shows a medium intensity that balances saturation and lightness, offering a pleasing greenish blue hue without appearing overly dark. The polish is excellent, and the gemstone has not undergone any enhancements, making it a fully natural specimen from Tanzania. At The Natural Gemstone Company we emphasize provenance and treatment disclosure, and this Tanzanian origin adds both geographic interest and a traceable story, qualities that discerning collectors and informed jewelers consider when assessing value and authenticity.

The exceptional sparkle of this aquamarine is a direct result of its internal crystal structure, optical properties, and the precision of its cut, all working together to maximize light performance. Aquamarine belongs to the beryl family, which crystallizes in the hexagonal system and exhibits a refractive index in the range around 1.577 to 1.583. That refractive index, combined with the carefully executed mixed brilliant facet arrangement, produces strong light return and lively scintillation. Although beryl has relatively low dispersion, which limits spectral fire, the cushion shape with rounded corners and strategically placed brilliant facets generates broad flashes of white light and strong contrast that the eye perceives as exceptional sparkle. The excellent polish enhances facet clarity and edge sharpness, allowing facets to act as crisp mirrors that reflect and refract light effectively. Inclusions noted at eye level do not compromise durability, and in some cases they contribute to the stone identification and natural provenance. For the educated buyer, this piece is valuable because it combines a substantial and well proportioned carat weight with natural, untreated color, precise cutting that accentuates brilliance, and a reliable origin. The Natural Gemstone Company stands behind the description and condition of this aquamarine, and can assist with further details for collectors, gemologists, or designers seeking a gemstone that offers both visual allure and documented authenticity.