Amber is one of the organic gemstones, being the time-hardened fossilized resin of pine trees, the now extinct pinus succinifera, and other trees. This aromatic resin oozed down the sides of the trees, as well as filling internal fissures, trapping debris, such as seeds, leaves, feathers and insects. The first stage involved the slow evaporation of volatile oils. The oils, called turpenes, could take anything from 100 to 1000 years to fully dissipate. Once completed the resin would become harder and could then be called copal. Following the dispersal of the oils the next stage is the cross chain linking of the molecular structure within the copal which is almost a kind of polymerization. This makes the copal harder and less brittle.
This second stage may take millions of years before the process turns the copal into something approaching the structure of amber. As geologic time progressed the forests were buried and the resin hardened into a soft, warm, golden gem, known as amber. Hence, Amber is the fossilized resin of ancient trees which forms through a natural polymerization of the original organic compounds.
In the Sambia deposit several types of fossil resins (pieces of varying sizes, the smallest only several millimeters in size, the biggest the size of an egg, and of varying colors, from blue, greenish, all shades of brown to tar-like black) with similar qualities are found along Baltic amber.
Big deposits of fossil resins especially rich in inclusions have been discovered in the Arctic, North America (Alaska), Yugor and Taymyr Peninsulas and in the Carpathian region, especially in Romania. They are opaque, reddish-yellow, dark red, blue, dark green, fluorescent, and stink of sulphur and petroleum when burnt.
In Sicily and in northern Italy deposits of dark red and yellow fossil resins of trees of the family Cupressaceae called Sicilian amber is found. Since the oldest times it has been used in the manufacture of adornments and Phoenicians knew about its deposits.
In Europe 50 types of fossil resins of different age are found.
The oldest known Asian fossil resins (sometimes pieces have the size of a head) are found in Birma. They are mostly opaque, dark brown, sometimes - red and yellow and in the 18th century single beads of these resins were used by Tibetan Buddhists for the decoration of their rosaries.
Fossilized insects are especially common in fossil resins found in Mexico, Dominican Island, and Haiti. So-called Mexican amber is a result of resins of leaf-bearing trees and is widely used in jewelry.
In Africa in the soil of no longer existing forests sub fossil resins of leaf-bearing trees are found and locals use them for making of adornments and amulets.