These earrings are a combination of vintage, upcycled & hand crafted. They have 925 sterling silver hooks, which means they are hypoallergenic. Dichroic Glass is a multi layer coating placed on glass by using a highly technical vacuum deposition process. Quartz Crystal and Metal Oxides are Vaporized with an electron beam gun in an airless vacuum chamber and the vapor then floats upward and attaches then condenses on the surface of the glass in the form of a crystal structure. The coating that is created is very similar to a gemstone and by careful control in thickness, different colors are obtained.