16.67 Ct. Blue Aquamarine from Brazil

This 16.67 carat cushion shaped aquamarine presented by The Natural Gemstone Company measures 17.77 by 13.54 by 10.66 millimeters, a substantial size that balances presence and wearability. The gem is expertly faceted in a mixed brilliant style, combining a broad, well defined table and a crown with modified brilliant facets, with a pavilion that integrates both brilliant and step fashioning to optimize return of light and color. With a depth ratio of 68.1 percent the stone exhibits a thoughtful proportioning that favors scintillation across the crown while retaining enough pavilion depth to concentrate tone and preserve durability. The finish is an excellent polish throughout, giving crisp facet junctions and mirror like facet planes that translate into strong light performance under both direct and diffuse illumination, and the girdle is consistent, allowing predictable setting behavior and minimal loss of weight to polishing.

The cutting approach on this specimen emphasizes a balanced trade off between brilliance and color saturation, characteristic of a mixed brilliant execution tailored for aquamarine, where too many shallow facets can wash out the delicate blue, and too many step facets can mute the lively flashes collectors seek. The crown presents modified kite and star facets that lead light into a layered pavilion where small step facets near the culet area act to deepen the blue, a deliberate choice for a light intensity gem to deliver perceived color without over darkening. Clarity is eye clean as evaluated at eye level, indicating inclusions are absent for unaided visual inspection, which allows the stone to showcase transparency and internal light travel without obstruction. Origin from Brazil is consistent with the stone s mineral character, including its crystalline habit and the clean, watery blue typical of Brazilian aquamarine, and the enhancement is a standard heat treated process that has been applied to reduce greenish undertone and stabilize the resultant blue, a treatment widely accepted within the trade for its permanence when the gem is handled under normal wear conditions.

On the Mohs hardness scale aquamarine, a member of the beryl family, registers between 7.5 and 8, placing it well above common jewelry minerals such as quartz at 7, and below the hardness of top gem materials such as topaz at 8, corundum at 9, and diamond at 10. This hardness profile means the stone offers good resistance to everyday abrasion and surface wear, but it is not impervious to sharp impacts or heavy knocks that higher hardness materials can endure. For this reason we recommend consideration of protective mounting styles, especially for rings intended for daily wear, such as bezels or halo settings that reduce the exposure of the girdle and corners, while allowing the mixed brilliant cutting to remain visually accessible. Routine care includes cleaning with warm soapy water and a soft brush to maintain the excellent polish and facet crispness, while strong chemical cleaners and prolonged exposure to high heat or rapid thermal changes should be avoided despite the stability of standard heat treated aquamarines. The Natural Gemstone Company can assist with advisory mounting choices and care recommendations, and we welcome inquiries from collectors and jewelers seeking technical documentation, detailed facet maps, or mounting prototypes to ensure this 16.67 carat cushion aquamarine performs to expectation in the chosen setting.