Vintage white gold ring with a central Verneuil padparadscha-color sapphire in millegrain borded bezel setting surrounded by 18 rose cut diamonds. Antique jewelry object group: engagement ring (or anniversary ring) Condition: excellent condition Country of origin: Belgium Style: Fifties (of the twentieth century) Period: ca. 1950 Material: 18K white gold Extra information: Verneuil - Auguste Victor Louis Verneuil was a French chemist (1856-1913) He invented a type of blowpipe (chalumeau) with which he was the first to lab produce rubies. This process is also sometimes referred to as flame fusion. His results were published in 1904. The apparatus is still used today (sometimes in banks of several hundred units) to make synthetic varieties of corundum and other synthetic gemstones. Other processes were developed but those are used less frequently, e.g. hydrothermal, flux fusion, and Czochralski. Padparadscha Sapphire - Natural Padparadscha is a delicate light to medium toned pink-orange to orange-pink hue corundum, originally found in Sri Lanka, but also found in deposits in Vietnam and parts of East Africa. Padparadscha sapphires are rare; the rarest of all is the totally natural variety, with no sign of artificial treatment. The name is derived from the Sanskrit "padma ranga" (padma = lotus; ranga = color), a color akin to the lotus flower (Nelumbo nucifera �Speciosa�). (from: Wikipedia) Diamonds: 18 rose cut diamonds. We do not have the weight of the diamonds which is normal in our trade when it comes to rose cuts. Note: All diamond weights, color grades and clarity are approximate since the stones were not removed from their mounts to preserve the integrity of the setting. Precious stones: One sapphire (lab produced) (also called verneuil sapphire), in Padparadscha-color with an estimated weight of approximately 4.40 crt. Birthstones: Diamond is the birthstone (or month stone) for April and sapphire for September. Hallmarks: "750" indicating 18K gold Dimensions: top of ring 1,35 cm (0,53 inch) x 1,70 cm (0,67 inch) Weight: 4,70 gram (3,02 dwt) Ring size Continental: 53 & 17 , Size US 6_ , Size UK: M Resizing: Free resizing (only for extreme resizing we have to charge). Reference N: 13290-0121 Copyright photography: Adin, fine antique jewelry