1.73 Ct. Cabochon Boulder Opal from Australia

This beautiful boulder opal from Australia, offered by The Natural Gemstone Company, is an outstanding example of how carat weight directly influences value and desirability in the opal market. At 1.73 carats, this oval shaped gem sits in a sweet spot where it is noticeably present in any piece of jewelry, yet still affordable compared with larger, rarer specimens. The dimensions of 9.40 by 6.91 by 3.45 millimeters give it a substantial face-up presence without being bulky, making it ideal for a classic ring or a refined pendant. Many opals under 1 carat can appear delicate or get visually lost in the setting, and conversely, larger stones can become prohibitively expensive or difficult to mount. This 1.73 carat weight therefore offers a perfect balance, delivering visible size and impact while preserving excellent value per carat. Because opal play-of-color is viewed across the surface area, a slightly larger table and broader span of material, such as with this stone, allows the multi color flashes to develop more dramatically, which in turn elevates its perceived quality compared with smaller, fragmented pieces.

Beyond weight, this gem stands out for its cut and finish, features that differentiate it from many mass-market doublets and assembled stones. It is a cabochon cut with a smooth domed profile, a traditional choice that maximizes the stone’s play-of-color and provides a comfortable, secure setting option. The polish is excellent, reflecting light evenly and enhancing the internal flashes of blue, green, and hints of warmer tones. This opal is an opaque boulder opal doublet, a popular and ethical choice for those seeking vivid color at a reasonable price. While solid black opals command top market prices due to their rarity, boulder opals are prized for their natural ironstone backing, durability, and striking color contrasts. Doublets combine a thin slice of precious opal adhered to a dark backing to intensify color and stability. Compared to inexpensive triplets that use a thin plastic cap and often display inferior luster and longevity, our doublet construction preserves the opal’s natural surface and polish, offering a superior appearance and a longer-lasting investment. The medium intense color intensity of this stone is a sweet middle ground, showing strong, lively color without the occasional over-saturation or artificial enhancement found in lower quality assembled pieces.

When you compare this piece to others on the market, its rarity and overall value proposition become clear. Many commercially available opals of similar dimensions are sold at lower weights, or they are offered as triplets or synthetics that imitate play-of-color but lack the depth and character of a true Australian boulder opal. A 1.73 carat weight in a natural doublet format with such even, multi-hued color and an excellent polish is uncommon at this price tier, because cutters and miners often partition higher quality seams into smaller yields to maximize the number of stones, making mid-size pieces like this more rare. The opal’s Australian origin further enhances its cachet, as Australian boulder opals are renowned for their vivid flashes and stable structure compared with some other sources. For the discerning buyer, this gem represents a smart choice: more presence and visual impact than a sub-carat stone, more durability and honesty of materials than many triplets, and better overall color performance than many mass-produced doublets. The 9.40 by 6.91 by 3.45 millimeter profile also allows jewelers to design settings that protect the stone’s edge and back, leveraging the natural ironstone backing characteristic of boulder opal to create secure, elegant pieces that wear well over time.

In short, this 1.73 carat oval multi color boulder opal doublet from The Natural Gemstone Company delivers a combination of weight, color, and craftsmanship that outperforms many of the alternatives available today. Its medium intense color intensity and excellent polish mean it will catch the light and hold the gaze, while the cabochon shape and thoughtful dimensions provide versatility for high-quality custom work. Whether you are comparing it to smaller sub-carat opals that lack presence, to synthetic imitations that lack depth, or to thin triplets that sacrifice long-term beauty, this piece stands apart as a well-balanced, rare opportunity to own an Australian boulder opal with genuine play-of-color and lasting appeal. If your priority is a gemstone that reads larger, performs beautifully in daily wear, and represents a smart investment in both aesthetics and rarity, this opal is an exceptional choice.