Art Deco opal and diamond ring in platinum

Art Deco opal and diamond ring in platinum (950). Antique daisy-shaped ring, centered with a large cabochon-cut opal set in a bezel, surrounded by twelve old-cut diamonds. The opal displays luminous violet, blue, and green hues with a hint of orange. The ring's setting is delicately crafted, decorated with scrolls. Art Deco period ring, circa 1930, France. Dog's head hallmark and goldsmith's hallmark (French state hallmark for platinum) Ring size: 51 EU or 5.75 US (resizing possible) Kitten dimensions: 18 x 14 mm Opal weight: 1.03 carats Estimated total weight of diamonds: 0.48 carats Condition: minor scuffs and scratches from use Weight: 8.18 g Gemology and Beliefs: There are several types of opal: precious opals and common opals. Precious opals, like this one, display play-of-color due to the light. They are composed of tiny, aligned siliceous spheres of the same diameter. When light hits the stone, and depending on the angle from which it is viewed, a play of light dances across the opal's surface. Common opals, on the other hand, do not display play-of-color; their spheres are disordered and of varying diameters. Light simply gives them a "milky" appearance. In the collective imagination, opal was believed to have the power to render one invisible. Hence its designation as "Patronus furum" (patron of thieves) at the end of the Middle Ages.