The tree species that produced amber are now extinct. They included cedars and other conifers and broadleaved trees. The most famous source of the world’s amber is the Baltic coast of Russia. In the western hemisphere, there are rich deposits in the Dominican Republic, Mexico, and the state of New Jersey.
Amber is of interest both for its decorative value and for the ancient, once living inclusions that it preserves. Capable of being highly polished, it is the oldest decorative substance known. It was familiar to Paleolithic peoples and to the Greeks and Romans, who used it extensively in jewelry. Pliny recounts several instances of its artistic uses. Baltic amber also contains succinct acid and is often called succinct. An essential oil, amber oil, is obtained from amber.
Leaves, flowers, insects, and small animals are frequently found in amber. Older fossils trapped in this way often represent the sole specimen of an extinct species. An especially rich bed of amber in New Jersey has yielded over 100 previously unknown extinct cretaceous species dating back as much as 94 million years. Because of ambers preservative qualities, the DNA of the specimens trapped inside is intact, affording scientists a unique opportunity to study the DNA of extinct species.