4.12 Ct. Black Opal from Australia

This black opal from Australia is a 4.12 carat oval, with precise dimensions of 15.08 by 8.44 by 4.68 millimeters, presented in a classic tablet cut that emphasizes a broad, shallow face and low profile. The specimen is opaque with a deep body tone characteristic of black opal, and it exhibits an intense color intensity dominated by vivid blue chroma. Under controlled viewing angles the stone reveals concentrated flashes of cobalt and indigo with localized areas of brighter ultramarine, the play of color presenting predominantly as broad flashes rather than fine pinfire, which is consistent with the tablet profile that prioritizes face up color saturation. Clarity is graded as very slightly included when evaluated at eye level, these are minimal internal features and surface characteristics that do not detract from the overall visual impact or structural integrity, and the lapidary work maintains even pavilion thickness to preserve stability while maximizing visible color. The polish is excellent, the surface is uniformly smooth and free from noticeable lapping lines, and the tablet geometry produces consistent light return across the face, optimizing the contrast between the dark body and the intense blue play of color.

From a technical and setting perspective this heat treated black opal has been stabilized to enhance body tone and color saturation, a controlled thermal treatment applied to improve overall appearance without altering the stone matrix or compromising hardness. The tablet cut and 4.68 millimeter thickness are deliberate choices that balance color presentation with durability, making this gem particularly suitable for low bezel settings or flush mounts where protection of the thin edge is a priority. For high contrast presentation consider white metals to accentuate the blue flashes, or a dark bezel for a seamless black onyx effect, while avoiding aggressive mechanical cleaners or ultrasonic baths to preserve polish and treatment stability. The Natural Gemstone Company offers this piece with full disclosure of origin as Australia and enhancement as heat treated, and we recommend professional setting and routine gentle maintenance to retain the exceptional face up color and fine polish achieved by the cutter.