Amber is referred to as petrified tree resin or sap. Amber deposits form when resins produced in forests are transported by water to oceans or lakes, where they are deposited into sedimentary layers. Once deposited, the resin chemically matures into intermediate forms called copals and finally into amber after millions of years. The amberization process is estimated to take between 2 and 10 million years. Check out that uv glow!