18.45 Ct. Boulder Opal from Australia

One beautiful translucent 18.45 carat trillion shape multi color opal sits at the center of this offering from The Natural Gemstone Company, a Boulder Opal that combines dramatic color play with a discreet, refined profile, a rare piece for collectors and designers alike. The tablet cut gives the stone a low profile and a broad face that displays its brilliant internal fire, dimensions of 39.22 x 14.03 x 4.98 mm provide a generous surface for the vivid color patches to dance across, and the overall silhouette is an elegant tapered triangle that reads modern while honoring classic opal character. The clarity grade is very slightly included evaluated at eye level, which means the natural inclusions are minimal and do not detract from the gem, rather they contribute to its authentic boulder personality. The polish is excellent, so the surface gleams and the play of color snaps crisply under different angles of light, making blues and greens, with flashes of turquoise and teal, come alive as the gem is moved. This opal has no enhancement, a pure natural specimen, and its Australian origin guarantees it belongs to the most esteemed tradition of opal formation, where many of the finest boulder opals are found embedded in ironstone matrices and trimmed to preserve maximum color.

As a salesperson and student of gemstones I like to explain how this particular specimen will behave once set and how it might best be appreciated, the tablet cut and relatively thin profile make it ideal for bezel set pendants, modern minimalist rings with protective settings, or as a striking centerpiece in a multi stone composition where the surface can face upward and capture light, the generous face of the trillion shape highlights broad color patches rather than narrow pinfire, which is perfect for designs that want a bold field of color rather than a delicate sprinkle of fire. Because it is a Boulder Opal the stone retains a natural backing that can add structural stability and a warm, earthy tone along the edges, a characteristic that allows jewelers to create settings that embrace the stone without heavy mounting, keeping the final piece comfortable and wearable. The vivid color intensity ensures that the play of color remains strong even under softer indoor lighting, so it performs beautifully both in natural sunlight where opal shows full spectrum brilliance and in ambient light where its deeper blues and greens create depth. For buyers who prioritize natural, untreated gemstones this opal is especially compelling, the no enhancement status confirms that what you see is the stone in its original state, with all the desirable quirks and personality intact.

Provenance, presentation, and service matter as much as the gem itself, and The Natural Gemstone Company stands behind this Boulder Opal with straightforward information and professional handling. Origin is Australia, a key point for collectors who value the geological pedigree of opals and the superior color potential found in Australian deposits, and the combination of weight at 18.45 carat and length across at 39.22 mm gives you a substantial wearable size that jewelers will appreciate when planning settings. If you are designing a signature pendant this shape and scale allow for dramatic yet elegant pieces, and if you are considering a bespoke commission our team can advise on orientation, edge retention, and backing techniques that will preserve the excellent polish while protecting the stone from knocks and abrasion. For those acquiring gems as long term investments, the rarity of large, vividly colored, untreated Boulder Opals with excellent polish and very slight inclusions is a compelling factor, and The Natural Gemstone Company is available to provide additional imagery, angles, or commentary to help you visualize the gem in your design. If you would like me to recommend mounting styles, matching accent stones, or to reserve this opal while you finalize a design, I am here to assist and to ensure the gem reaches you in the best possible condition, accompanied by honest, detailed information about its characteristics and natural origin.