Kieselstein-Cord Peridot Diamond Yellow Gold Ring. Beautifully designed and made of the finest materials, this gemstone ring from Kieselstein-Cord is absolutely divine! The ring is made of 18K yellow and boasts shanks and a bezel set with diamonds. Lastly, a single ~5.40ct peridot main stone adds a hint of color to the overall design. Circa 20th century.