Kiezelmarmer in groen, oranje, blauw en geel (1800 - 1969) by anonymous https://www.rawpixel.com/image/13735564/kiezelmarmer-groen-oranje-blauw-geel-1800-1969-anonymousFree Image from public domain licenseSidewall cut stone imitation. Original public domain image from Smithsonian. Digitally enhanced by rawpixel. https://www.rawpixel.com/image/9851134/image-wallpaper-background-iphoneFree Image from public domain licenseDecorative Paper from page 712 of Sketches in Spain during the years 1829, 30, 31, &32; containing notices of some districts… https://www.rawpixel.com/image/2356329/free-illustration-image-pattern-marbled-paper-public-domain-green-marbleFree Image from public domain license