The golden ratio ?=1.618 is known for its appearance throughout nature. The Medium Golden Ratio earrings in our Iconic Mathematics Collection showcase the Fibonacci Spiral inscribed in squares of sizes 1, 1, 2, 3, and 5 --- the first Fibonacci numbers! Perfect for an aspiring young mathematician who wants to show off their love of mathematics! Dimensions: 0.56in x 0.98in (13mm x 25mm). Also available in a smaller size. Our Metal jewelry is created through a lost-wax casting process. A mold of the object is 3D printed in high-resolution wax, a plaster mold is created around the wax, and the wax is replaced by molten metal. Brass and Bronze jewelry will patina over time. Silver and Rhodium Plated Earrings feature stirling silver earwire. Brass and Gold Plated Earrings feature gold-filled earwire. Rose Gold Plated Earrings feature rose gold-filled earwire.