A zirconia set is a collection of jewelry or decorative items made from zirconium dioxide, a white, crystalline oxide of zirconium. Zirconia sets can include items such as rings, earrings, necklaces, and bracelets, and are often used as an affordable alternative to diamonds. They are known for their durability, brilliance, and affordability, making them a popular choice for those looking for beautiful and timeless pieces.