According to the San Francisco Gem and Mineral Society, amber comes from evergreen trees, such as pine trees. Authentic amber is tree resin that has been hardened over millions of years.
The San Francisco Gem and Mineral Society explains that amber is the result of crystallized, fossilized tree resin, rather than sap, and may come from sources that include cherry, plum or redwood trees. Pine trees are the most common source of amber. Amber from redwood trees is among the rarest types of amber available.
The color of amber is based on the conditions where the amber was formed. For instance, deep red amber is usually formed from pine and redwood trees, while green amber contains decayed organic materials. Large amounts of amber can be found in the Baltic region.