15.61 Ct. Blue Aquamarine from Brazil

This 15.61 carat cushion shape aquamarine from Brazil presents a study in proportion, optical clarity, and cutting precision. Measuring 17.15 by 13.80 by 10.28 millimeters, the stone exhibits an overall depth of approximately 60 percent, a dimension that sits squarely within the ideal range for cushion cuts intended to balance face-up size with internal light return. The gem has been faceted in a mixed brilliant style, combining a brilliant-cut crown with a pavilion that incorporates both brilliant and modified step elements. This faceting strategy maximizes scintillation across the table while preserving large, even flashes from the pavilion, producing both broad white brilliance and numerous small, lively scintillas. The excellent polish and careful facet junctions yield crisp facet reflections and minimal surface disruption, which together contribute to a clean visual presentation without windowing or extinction. As a beryl, this aquamarine will sit around refractive indices of 1.577 to 1.583 and a specific gravity near 2.70, and those intrinsic optical constants are well exploited here by the cutter to achieve an even, watery dispersion and a calm, aquatic luster.

Clarity for this specimen is described as very very slightly included when evaluated at eye level, a grade that communicates exceptional transparency. The eye-level inclusions are minute and peripheral, they do not interrupt the overall light path or create negative pinpoint contrast under normal viewing conditions, and they are essentially invisible once mounted. Light color intensity is modest, presenting a delicate, light blue that reads as crystalline and pure rather than strongly saturated. Importantly for connoisseurs, this aquamarine is unenhanced, no heat treatment or irradiation has been applied to alter hue or clarity. Natural, untreated aquamarines of this size and eye-clean character are uncommon, particularly from Brazilian material where top-quality crystals yield superior cutting potential. The mixed brilliant cut and the stone’s proportions were chosen to emphasize face-up brilliance and preserve as much of the natural weight as possible, a compromise that results in both a generous optical presence on the finger and efficient retention of carat weight for collectors who value natural state and provenance.

When compared to famous gemstones in history, this aquamarine occupies its own niche of wearable museum-grade refinement. It shares the clarity and crystalline transparency associated with museum aquamarines such as historically noted large Brazilian specimens, yet it is presented in a finely wearable 15.61 carat dimension rather than in the colossal sizes reserved for display. Unlike heavily saturated sapphires or the deep velvety blues associated with Kashmir or Ceylon blue sapphires, this aquamarine offers a serene, maritime blue that reads as lighter in tone but exceptionally pure and lucid, making it comparable in perceived value to historically celebrated gems where clarity and color purity were prized over saturation. In terms of brilliance and cutting philosophy, the mixed brilliant approach used here reflects the same modern refinement seen in high-end reinterpretations of classic stones, where the cutter intentionally balances dispersion and scintillation rather than pursuing absolute fire at the expense of color and weight. The absence of treatment further distinguishes this piece, because many commercially available aquamarines undergo heat to remove greenish tones and enhance blue saturation. The Natural Gemstone Company is presenting a stone whose natural state, precise cutting, and eye-clean clarity together deliver a level of authenticity and aesthetic continuity that collectors and jewelers seeking historically resonant yet contemporary gems will appreciate.

For the client considering settings and long-term appreciation, this cushion aquamarine’s dimensions and optical behavior favor open, low-profile prong settings that allow light to enter the pavilion freely and preserve the stone’s face-up brilliance. A halo of small accent stones will increase perceived size without masking the gem’s delicate hue, while a four-prong basket or a bezel with well-placed openings will protect the girdle and preserve the excellent polish over time. From a gemological standpoint, the combination of Brazilian origin, natural color without enhancement, mixed brilliant faceting, and an eye-level clarity assessment of very very slightly included confers both immediate wearable appeal and longer-term collector value. The Natural Gemstone Company stands behind this aquamarine’s measured proportions and documented characteristics, and we emphasize that its unique value lies in the rare convergence of substantial carat weight, meticulous cutting, natural condition, and the crystalline, sea-blue personality that only fine aquamarine can deliver.