0.57 Ct. Cabochon White Opal from Australia

This listing describes one translucent White Opal weighing 0.57 carat, fashioned into a classic oval outline with precise dimensions of 6.91 by 4.80 by 2.90 millimeters. The gem is cut as a domed cabochon, a cutting style deliberately chosen to optimize the internal diffraction phenomena responsible for play of color while preserving material thickness for durability. The material presents multi color flashes across a predominantly pale body, with medium light color intensity which allows vivid color patches to appear against the soft white ground. Clarity is graded as very slightly included evaluated at eye level, indicating small internal features that are discernible without magnification but do not disrupt the overall visual effect. Polish is rated excellent, with a smooth, mirror like surface that enhances color transmission and minimizes surface irregularities when set, and no enhancement has been applied to this stone, confirming it as a natural, solid White Opal originating from Australia.

From a lapidary and gemological perspective the cabochon exhibits controlled dome height and well centered color areas, evidence of experienced orientation during cutting to present the strongest color play in typical face up viewing positions. The cabochon cut avoids facets entirely, relying on a convex geometry to concentrate and reveal the diffraction of light by silica spheres within the opal microstructure. This internal structure, composed of ordered hydrated silica spheres, produces color by diffraction rather than by selective absorption, and the multi color character observed in this specimen suggests a range of sphere sizes and packing arrangements that yield green, blue and occasional warmer tones when illuminated. The measurements and 2.90 millimeter thickness provide a balanced depth to support stable mounting and to maintain sufficient volume for color to develop without compromising the cabochon silhouette. As a White Opal the background body tone is light, which typically allows play of color to manifest as discrete patches and flecks across the dome, and the very slightly included clarity grade means that these features will remain the focal point under normal viewing conditions. For comparison, the material falls within typical opal optical parameters, with refractive index near 1.44 to 1.46 and specific gravity in the range of 1.98 to 2.20, and it requires the same handling considerations common to natural opal, including sensitivity to sudden temperature changes and aggressive chemicals.

For jewelry applications and longevity the gem benefits from protective mounting choices that respect opal hardness and cleavage tendencies. On the Mohs scale opal is approximately 5.5 to 6.5, and the recommended settings include low bezel seats or halo styles that shield the cabochon edge from impact while allowing the dome to present its color freely. Prong settings may be used for lighter wear items, but for rings a full bezel or partial bezel with a channel shoulder will significantly reduce risk of edge chipping. Because this is a solid White Opal with no enhancement, it is well suited to fine custom pieces where natural provenance is desired, and the Australian origin adds market value and desirability among collectors. Care instructions are straightforward, clean gently with warm soapy water and a soft brush, avoid ultrasonic or steam cleaners, and avoid exposure to harsh solvents and rapid temperature shifts. The Natural Gemstone Company offers this stone as a ready to set, ethically sourced specimen for designers and connoisseurs who appreciate precise cutting, natural material integrity, and the subtle complexity of a multi color White Opal. If you would like additional images under different lighting angles or measurements for setting seats, The Natural Gemstone Company can provide those specifications to facilitate design integration.