Dimensions: 0.325 " x 0.5" ; 8mm x 12mm The BRIGHT MOSAIC line features dichroic glass: it is the reason these earrings are so shiny bright and cute. A coating of metals is encapsulated between the two glass layers, with interesting reflective properties. Depending on the angle from which you look at them, the color shifts and changes. Some of these designs are single-color, and these shift only in the intensity of their color. Others are two-color, and will shift from red to silver, for example, or from blue to green. The ear wires are nickel-free Argentium silver and come with a silicone ear back.