Baltic Amber is a fossil of resin that is like sap that formed over 45millions years old from the Baltic sea region of Europe. Although not a mineral, it is generally classified as a gemstone. A common misconception is that Amber is made of tree sap. The sap is the fluid that circulates through a plant's vascular system, while the resin is the semi-solid amorphous organic substance secreted in pockets and canals through epithelial cells of the tree.