75mm Loose Black Opal Sphere Appraisal

7.5mm Loose Black Opal Sphere

This item is a loose, spherical gemstone identified as a black opal, measuring approximately 7.5mm in diameter. The stone exhibits a dark body color, which serves as the base for its play-of-color. In the provided imagery, the specimen displays a silken luster with hints of blue and green spectral flashes across its surface. The shape is a fully rounded bead or sphere rather than a traditional cabochon, suggesting it may have been intended as a center bead for a high-end jewelry piece or a stud earring. The surface appears smooth with no immediate signs of significant crazing, though a slight cloudiness is visible which is characteristic of the opal's amorphous silica structure. The craftsmanship is evident in the symmetrical high-polish finish. While the provided context labels it 'black opal', the visual representation under this specific lighting shows a lighter, almost greyish-blue pearlescence, which can occur depending on the orientation of the stone and the light source. There are no visible maker's marks or stamps as it is a loose stone. Its condition appears stable with no major chips or fractures visible to the naked eye, though microscopic examination would be required to rule out internal fissures known as 'crazing' common in older opals.