11.58 Ct. Boulder Opal from Australia

One natural Boulder Opal offered by The Natural Gemstone Company, this specimen weighs 11.58 carats, and presents an oval outline with overall dimensions of 19.98 x 14.63 x 4.44 mm. The gem is opaque, and is fashioned in a tablet cut which optimizes the surface play of color across a flattened dome. Color intensity is classified as intense, and the surface finish exhibits an excellent polish that enhances the opal character at every viewing angle. The piece is a multi color display, originating from Australia, and it has not undergone any enhancement, keeping the material in its natural state for accurate assessment and responsible sourcing.

Visually the stone exhibits a field of saturated blues and greens, with interspersed flashes of purple and hints of warmer tones in localized areas, together producing a complex and attractive color mosaic. The Boulder Opal matrix is apparent at the stone edges, providing a natural ironstone contrast that helps to define and intensify the opal color patches. The tablet cut creates a broad surface plane for the opal face, and the shallow profile, at 4.44 mm thick, is well suited to settings that require a low profile, including bezel and inlay work, as well as modern pendant designs where the color display is the primary focus. The oval outline measures nearly 20 mm by 15 mm, which is a comfortable size for a central element in small to medium statement pieces, allowing the color play to remain visible from multiple angles under typical indoor and outdoor lighting.

From a gemological perspective this Boulder Opal presents characteristics that are desirable to collectors and designers alike, particularly due to its natural, untreated condition. The ironstone inclusion and matrix are typical of Boulder Opal, and they contribute to the stone stability by providing a strong backing to the opal layer, while also contributing to the aesthetic by breaking up the play of color with organic detail. The tablet cut, combined with an excellent polish, minimizes surface light leakage and promotes vivid color reflection, especially in the blue and green spectral ranges observed. The stone should be handled with the usual care appropriate for opal materials, including avoidance of extreme temperature shock, prolonged exposure to chemicals, and abrasive cleaning agents. Routine cleaning with a soft cloth and mild soapy water is recommended, and any professional setting or repair should be carried out by a jeweler familiar with opal mounting techniques to maintain the integrity of both the opal layer and the ironstone matrix.

For applications in jewelry and design, this Boulder Opal lends itself to a variety of secure mounting options, including closed bezel settings that protect the stone edge and expose the face for maximum color impact, and flush inlay installations where the low profile and tablet form are advantageous. The inherent contrast between the opal color patches and the ironstone matrix can be emphasized by warm metal choices, or it can be presented in a subtler manner with darker alloys that allow the play of color to dominate the visual field. As an untreated Australian Boulder Opal, this piece is documented by The Natural Gemstone Company for origin and enhancement status, and additional documentation or high resolution imagery can be provided upon request for design development, appraisal, or insurance purposes. If further measurements, additional angles, or setting recommendations are required, our team is available to provide detailed assistance, ensuring the stone is matched to the intended design and maintained for long term enjoyment.