Amber

Amber is a fossilized resin exuded by some species of trees. As opposed to sap which is the fluid that circulates through a plant's vascular system, resin is an organic substance secreted by a plant's epithelial cells. Many types of trees have produced resin throughout Earth's history, although most are within the tropical legume and araucarian families.

WHY IS RESIN PRODUCED?
It's thought that some trees produce resin as a form of protection due to injury and possible disease by effectively sealing off the wound (broken branch, etc.) much like a bandage does on humans.

HOW IS AMBER FORMED?
Resin is composed of nonvolatile and volatile terpenoid fractions. Once the tree starts secreting resin, the volatile terpenoids begin to evaporate and dissipate through a progressive oxidation and polymerization of the original organic compounds in the natural tropical forest conditions. Over a period of 50 to 1.6 million years (depending on the specific geological and environmental setting) only the nonvolatile terpenoids remain and become fossilized, producing amber.

Diptera: flies and midges - Dominican Amber (23 to 30 million years old)

Coleoptera - Platypodidae - Platypus sp. pinhole borer - Dominican Amber

Mexican Amber - Chiapas, Mexico

WHAT'S THE DIFFERENCE BETWEEN AMBER AND COPAL?
Both amber and copal start from the same resin, although what distinguishes them from each other is their resulting chemical make-up due to age.
Resin is secreted from the tree, hardens and becomes copal. As the hardened copal is exposed to the environment (often tropical and humid conditions), volatile chemical elements within the resin evaporate and dissipate. This oxidation and polymerization of the copal alters it's composition and essentially fossilizes, or changes it, into a substance different from the original resin. The altered (fossilized) resin is called amber. This fossilization process can take anywhere from 50 years to 1.6 million years to complete.
Copal = immature, non-fossilized resin.
Amber = mature, fossilized resin.

Due to it's sticky nature, sometimes items are caught and trapped in the resin as it is secreted from a tree. These items can range from pieces of bark, leaves, insects, flowers, and more rarely amphibians and mammal hair to name a few. Items trapped in hardened resin (both copal and amber) are called inclusions. Inclusions help to shed light into the environment surrounding the resin prior to it's hardening. As such, inclusions of insects and plants found in copal tend to be of extant species due to it's rather young age. Inclusions found in amber tend to be of extinct species due to it's relatively much older age. Inclusions in amber are far more rare than in copal, and often times add value to the amber for which they are entombed.

TYPES OF COPAL AND AMBER
Copal and amber are found in a number of locations throughout the world. The below table summarizes some of the best-known current localities of copal and amber deposits.

VALUE, FAKES & MODIFIED SPECIMENS
Amber specimens have been valued by countless cultures since the Paleolithic to modern times. There is evidence of amber jewelry in the Neolithic Period, amber found in tombs of the Babylonians and Egyptians, as well as Roman coinage made from amber. Following the knights return from the Crusades and their control of the Baltic sources of amber, the material was sought after for adornment of religious objects. In the 18th century, amber was used in concert with gold as the primary material in the construction of the spectacular Amber Room in Prussia. (The original Amber Room is still lost since its disappearance during World War II.)Today, amber is used for jewelry, carving of religious and decorative objects, and for scientific study and collection purposes. Amber truly has been valued and traded for centuries.

Generally, the commercial value of amber specimens is related to its durability, rarity, age and inclusions of extinct and organic species. Due to it's timeless value, amber is routinely faked. Forged specimens can be routinely found in shops, trade shows, as jewelry adornments and on the internet. Realistic amber fakes can be made with glass or a host of plastic-like materials such as resin, casein and celluloid. All of which look very similar to amber without performing additional tests. Additionally, copal is often-times sold as amber...both knowingly and unknowingly by the seller. Amber can be modified by enhancing it's color. While this is still considered to be natural amber by form, the piece is not in it's true, unaltered state as it was found.

Amber specimens which contain organic material (inclusions) are rare. Often times, the addition of an insect, leaf or other organic material in a piece of amber will raise the value. Depending on the rarity and amount of organic material in the specimen, inclusions may raise the value by a substantial amount. As such, forgers have developed ways of adding "fake inclusions" into genuine amber specimens. Organisms may be artificially placed within a crack, or inserted in a hole and then sealed within. Sometimes an entire "amber specimen" can be fake, with a resin or glass body and fake inclusions within. I routinely see entirely fake amber specimens with dragonfly or lizard inclusions being sold on ebay. As with the purchase of many other minerals and fossils, it's buyers beware when purchasing amber specimens. Always purchase from a reputable seller, and do research on identification of fakes prior to purchasing.