Type of jewel: Vintage 1920s Art Deco diamond and onyx ring Condition: In well-preserved condition, especially given the jewel`s age. Style: Vintage 1920's Art Deco Style characteristics: Abstract motives and geometrical forms are quite typical for the Art Deco period. Era: ca. 1920 Material: 18K white gold (touchstone tested) Diamond(s): Three rose cut. - We understand that private buyers may expect diamond weights to be provided, but in the case of rose-cut or senaille diamonds, this is simply not standard practice among industry professionals specialising in antique and vintage jewellery. Unlike brilliant-cut diamonds, where weight correlates with diameter, rose cuts vary in thickness, making weight estimation impossible once set. Providing such figures could lead to unnecessary debates, as rose-cut diamonds were traditionally valued for their visual effect rather than intrinsic worth. Even major auction houses like Sotheby’s and Christie’s rarely list their weight, except for exceptionally large stones, where diameter is often provided instead. - All diamonds, regardless of their size or shape, in our vintage and antique jewellery are verified as 100% natural by the IJGC laboratory. Precious stone(s): Two onyx baguettes Birth and month stones: Diamond is the birthstone (or month stone) for April and Onyx is the birthstone (or month stone) for July. Hallmarks: "18K" suggesting 18K gold Dimensions: band width top of ring 0,45 cm (0,18 inch) - See picture with a ruler in cm and inches Weight: 1,90 gram (1,22 dwt) Ring size: EU-53 & 17 , USA-6¼, UK-M Ring sizes are professionally measured and rounded to the nearest millimetre; slight variations are standard and do not affect wear. Adin reference Nº: 26019-0134 - All jewels are delivered in an Adin jewellery box. Boxes shown in photos are display props unless stated otherwise. - Every piece is accompanied by an Adin certificate of authenticity for your piece of mind. Adin has specialised in antique and vintage jewellery in Antwerp for over four decades. We maintain professional memberships and affiliations that reflect our ongoing commitment to standards, research, and responsible trade practice. - Shipped insured and registered. Collection in person is also welcome. - For shipments outside the EU, import duties and other charges may apply. We advise checking this in advance. - We invite you to browse through our customer feedback to discover the level of satisfaction we consistently provide. - See more of our pieces: https://auction.catawiki.com/lotsfrom/Adin - Antique and vintage jewellery may show evidence of past repairs or restoration, reflecting normal wear and period use. We present pieces in an authentic state and do not routinely remove surface marks or apply rhodium plating to white gold. If you prefer a brighter finish, you may choose a cosmetic refresh by a local goldsmith.