This Green Girl Studios knowledge tree pendant is perfect for those who love to learn. It has a regal and antique-style flare, which can especially be appreciated by book lovers. A detailed and flourishing tree is depicted on the front, with the word knowledge etched into the back. Like a tree we grow with knowledge everyday. Green Girl Studios uses the highest of quality material and nothing toxic, leaded, or bad for the environment. Bronze is derived from copper and tin. This piece measures 30 mm in diameter, 3 mm thick, and with a 2 mm hole.