Many of the standards are based on the Baltic amber market, the oldest and most prolific source since early history. Baltic ambers are those that wash up on the shores of the Baltic Sea in northern Europe. They are also found by mining in several areas of Scandinavia and northeastern Europe. Poland, Russia and Lithuania are well known for their amber markets, and amber features prominently in the jewelry designs of this region. Baltic amber can vary widely in their appearance, but they are all at least 10 million years old (most are 30-40 million years old) and all were produced by now-extinct trees known as pinus succinifera.