Greece is famous for the production of mastiha, or mastic, a tree resin collected from mastic trees that flourish in the distinct climate of Chios. Just 1 kilogram can retail for about $350. Today, it's known as "white gold" for its presumed health benefits and various uses in gum, cosmetics, and food. But harvesting this resin isn't simple. It requires farmers to first hurt the trees with as many as 600 cuts into each one's bark. It's only after each droplet has been collected by hand that the resin can be turned into products used around the world. So, what exactly is mastic resin used for? And why is it so expensive?