18.45 Ct. Boulder Opal from Australia

One translucent boulder opal, weighing eighteen point four five carats, presented in a trillion shape with a tablet cut, offers a distinctive combination of form and color. The stone measures approximately thirty nine point two two by fourteen point zero three by four point nine eight millimeters, and displays a thin, tapered profile that is characteristic of tablet cutting methods applied to opal material. Originating in Australia, this specimen has not undergone any enhancements, and its natural surface and ironstone backing remain evident, confirming its classification as a genuine Boulder Opal. The gem exhibits vivid color intensity across its face, and an excellent polish that enhances the clarity of the play of color while preserving the natural contours and matrix of the host rock.

From a gemological perspective this opal merits attention for several key attributes. The clarity has been evaluated at eye level as very slightly included, meaning that inclusions are minimal and do not materially detract from the overall appearance when viewed without magnification. The tablet cut produces a broad, flat display surface that emphasizes the dynamic color flashes and allows for efficient use of the stone in settings where a low profile is desirable. Color is predominantly in the blue and green range with multicolored flashes observable with movement, offering depth and directional character as light interacts with the opal structure. The stone presents a fine balance between translucency and saturation, enabling internal color play to be seen against the ironstone matrix, which provides natural contrast and stability.

Practical considerations for design, care, and presentation are straightforward given the material and dimensions. The elongated trillion outline makes the stone suitable for streamlined pendant designs, bezel inlays, or custom settings where a slender, tapered motif is intended. Due to the opal class hardness range and the thin tablet profile, careful protective setting choices are recommended in high wear applications, and impact resistance should be considered when specifying mounting details. The opal should be protected from sudden thermal shock and harsh chemical exposure, and routine cleaning with a soft cloth and mild soapy water is advised while avoiding ultrasonic and steam cleaning. Provenance documentation accompanies the description, and The Natural Gemstone Company stands behind the stated attributes including weight, dimensions, cut, clarity, color intensity, polish, enhancement status, and Australian origin. For design planning or further technical information additional images and measurements are available upon request from The Natural Gemstone Company.