These Celtic post earrings feature simple elegance for those who prefer posts. 1/2" Square. These Celtic earrings are made of Sterling Silver. Our silver jewelry is made of Sterling Silver alloy which is 92.5% of silver and 7.5% copper. Pure silver is too soft for making jewelry and the addition of copper gives the resulting alloy strength while preserving ductility and beauty. Sterling Silver alloy originated in Europe in the 12th century in northern Germany. Please check our other jewelry sections for more interesting items.