Fossil Amber

The perfect fossil preservative

Of related interest:
Fossil Amber Gallery
Fossil Insects (Many specimens are amber inclusions)

Fossil Amber or Fossil Resin

Phasmida or Walking Stick in Fossil AmberAmber is the popular name for fossilized resin of botanical origin. The proper scientific terminology is fossil resin, but we will use the terms amber and fossil resin interchangeably. The word amber also denotes a golden color that amber predominately reflects (recall that when human eyes see color, it is actually the portion of the visible light spectrum that an object reflects that is detected). In fact, amber reflects many frequencies of light, including red, green and blue that together constitutes the entire visible spectrum. Archeological findings show that amber was one of the first materials prehistoric humans used for ornamentation, with instances dating back as far as 30,000 years. Use of fossil resin for jewelry and other decoration continues unabated, and amber is often considered as a gemstone.

Amber is also valued for its botanical and animal inclusions that are trapped by the sticky resin as it flows as sap, which is also organic. Of course, other life is captured including microscopic bacteria that often produce gas bubbles, and various fungi. Both the botanical and animal inclusions not only add beauty, but also are of potential Isopod Crustacea in Fossil Amberscientific value in the study of taxonomy and evolution. Animal inclusions are usually invertebrates, specifically arthropods, and only extremely rarely a vertebrate such as a tiny lizard. Fossil resin inclusions are predominately insects, which should be no surprise since botanical resin is an evolutionary adaptation of plants that is, in part, for protection against insects.

Fossil Amber Chemistry
Fossil resin's molecular constituency is mainly carbon and hydrogen atoms that readily form hexagonal rings. Molecular bonding between the rings increases over time (called polymerization), and the sticky resin becomes hard. There are other types of atoms in trace to larger amounts that alter physical properties and may be substrates to certain organic solvents. For all practical purposes, the hardened resin, or amber, is a "plastic". Just when the resin becomes amber, or a fossil, is not defined, and is perhaps not definable. It is even contentious, since fossil resin is a commercial product in a competitive market. Younger amber is often called copal, though it is essentially as hard and its physical properties differ little from older resins.

All fossil resins are substrates for both hydrophilic (e.g., alcohol or acetone) and lipophilic (e.g., benzene) organic solvents and will disolve in them. The solvents will create various weak chemical interactions with the resin in order to solubilize it. The most common of these interactions are the relatively weak van der Waals interactions (induced dipole interactions), the stronger dipole-dipole interactions, and the even stronger hydrogen bonds (interaction between O-H or N-H hydrogens with O or N atoms).

Diamonds (and most mineral based gems) are forever, but fossil resin (amber) is not. As an unstable organic polymer, amber is biodegradable, just like a plastic milk jug or fiberglass boat. Its many weak covalent bonds and weaker hydrogen bonds are easily broken, a process that is accelerated by electromagnetic radiation of all frequencies and heat; ultraviolet is especially damaging (do not expose amber to sunlight), while visible and infrared much less so. Thus, while amber is, in a sense, the perfect preservative of fossils, once removed from the environment in which it formed, it is destined to crumble into dust; the time is long compared to the human lifespan, but essentially instantaneous on a geological timespan. Diamonds, on the other hand, go on forever.

Amber, Natural Selection and Chemical Warfare
Fossil resin (a.k.a., amber) is the result at least in part of nature's oldest drama, predator versus prey. Science does not yet know when it appeared in the Kingdom Plantae's arsenal of survival tactics, but natural section has conserved and probably diversified its usage. In temperate climates, the pines are prodigious producers of resin, which is used to make turpentine. In tropic climates, the genus Hymenaea, a timber tree, is the prolific producer. The evolutionary advantages of resin are varied. The resin is exuded to seal wounds such as from wind, fire, lightening or insect predation. Resin also contains a diversity of chemical defensive weapons. Some of these repel insects, and others attract insects that attack harmful insects, or attract parasites of insects that attack the plant, or are toxic to harmful fungi; in short a diverse chemical arsenal.

A Container for the whole Tree of Life
In terms of the Tree of Life, amber is most interesting since it entombs all three domains, Arachaea, Eubacteria and Eukarya. Archaea and eubacteria microbes are, of course, everywhere and surely embedded in the amber at high density. Interestingly, it is possible that some microbes. Still controversial finding a decade old claims to have recovered from the gut of a Hymenoptera from 30 million year old Dominican amber some three-dozen species of bacteria from ancient spores that grew on culture plates. The bacteria are from the extant genus Bacillus, a group that go dormant forming spores. Interestingly, Bacillus thuringiensis is used in the biological control of insects. Bacillus thuringiensis parasitizes the caterpillars of some harmful moths and butterflies. Spraying or dusting plants with its provides some protection against gypsy moth, tent caterpillar, and the tobacco hornworm. The bacteria has a gene that produces a toxic chemical warfare. The gene for this toxin has also been introduced into some crops.

Fossil Amber Ecosystems
One way to view amber is as a sealed unit containing a cross section of an ancient ecosystem with all its intricate predator-prey as well as beneficial symbiotic systems (e.g., termites as the methane produced by symbiotic bacteria that digest fiber in the termite gut). Fossil resin is a superb preservative, with organisms such as insects and spiders preserved in full three-dimensionality and in living color. To some degree, even, nucleotide sequence from ancient DNA is preserved, although resurrection of a Jurassic dinosaur is clearly science fiction.

Amber's Geographic Dispersion
Amber comes from throughout the world, even the Arctic. However, in terms of commercial availability, the Baltic area of Europe produces vast amounts, followed by the Dominican Republic in a distant second, with minor amounts coming from Central and South America, and more specifically, Mexico and Colombia, respectively. Amber from other localities is miniscule.

Baltic Amber
An enormous amount of fossil resin is extracted on the shoreline of the Baltic Sea, and these strata are dated to be Eocene in age, give or take a few million years, thus making it some of the oldest amber that is available in commercial quantity. The largest Baltic amber mine is in Kaliningrad, Russia, but Baltic amber is also found in Lithuania, Latvia, Estonia, Poland, Russia, and sometimes washes ashore far away in Denmark, Norway, and England. Fossil inclusions are relatively rare, almost always in isolation and usually tiny, and the amber is normally occluded with botanical debris and bubbles; for this reason, fossil specimens are best made viewable in pieces cut to small size prior to polishing, and pictures many times require a trinocular microscope.

Dominican Amber
Geological data for amber from sedimentary deposits in the Dominican Republic predict an age dating to the Oligocene, in the range of 20 to 30 million years old, presuming the resin is a primary in situ deposit, and not a secondary deposit by transport/erosion etc. Dominican amber from Cotui, however, is Pliocene or Pleistocene, has larger and more insects, and is otherwise indistinguishable from older material from the dated sedimentary deposits. Since resin-producing trees are still abundant in this tropical island area, resins of any age are possible. The older fossil resins are from deep mines in the hillsides, and the extraction can be a dangerous proposition, with risk of being buried in a cave in. The insect inclusions in Dominican amber are fairly abundant, the insects larger, and the amber of higher clarity than found in Baltic amber. Though uncommon, fossil association are found more frequently in Dominican amber.

Colombian Amber
Far and away the most fossiliferous amber originates in Colombia, albeit it has become fairly widespread that all fossil resin from Colombia is called copal. The amber versus copal distinction is lost on many geologists and paleontologists that are aware that scientific data is unavailable to determine the age of fossil resins from this region. The consensus age estimate seems to be Pleistocene (up to 2 million years old), but estimates range to the Lower Miocene (about 20 million years old). Though geological studies are unlikely soon in this region that is controlled by drug cartels, it seems safe conjecture that there is a large range of age across different deposits, similar to that of the Dominican Republic. In the Dominican Republic, mine cave-ins are a danger for some of the older deposites; in Colombia the danger might be AK47's of the drug producers. Whether amber or copal, young or old, the fossil insects and other arthropod inclusions and their associations are truly sublime in Colombian amber. Perhaps the most impressive aspect of Colombian amber to those with a scientific propensity is the wonderful fossil associations. So many species are often in association that the specimen will represent an ecological cross section of an ancient rainforest.

Amber versus Copal
- Obfuscation not science
A few more words about the distinction between amber and copal, both slang terms without scientific basis, is warranted. We absolutely disdain scientific prostitution, and are therefore compelled to expose it. Fairly widespread on the Internet and in several popular and otherwise wonderful "amber" books are statements that there is no amber from Colombia, and that Colombian amber is "young" copal, because it has not yet undergone some mythical transformation that is never described. This is a perfect example of the old saw: "if you tell a lie enough times, it becomes (perceptive) reality"; such obfuscation is perhaps to be expected from commercial interests, but is shameful when individual scientific credentials are used as justification. Any polymer chemist studying fossil resin chemistry would quickly discern that the essential constituents and chemical binding characteristics are demonstrably the same in all fossil resin, regardless of locality, and regardless of age, once the material has hardened - there is no important scientific distinction to be made. Several of these sources offer as fact a small sample from one locality in Colombia carbon dated at a couple hundred years old. They then make the banal extrapolation that the small sample's age can be extrapolated to all fossil resin in what is a huge country where trees have been producing resin for as long as anywhere else. Besides the idiocy of presuming all fossil resin is the same age as the one sample, they neglect to point out that the evolutionary adaptation of resin production has not been eradicated from plant genomes. That is, plants continue to make resin, and thus the only plausible assumption is that fossil resin exists in a continuum of ages to present in all places where it is found, unless the botanical source has disappeared. It is unfortunate that a few gemologists and others not trained in science continue to promulgate scientific poppycock. For a few more words on this, Dr. Robert E. Woodruff, Emeritus Taxonomist, Florida State Collection of Arthropods, who has collected and studied fossil resin and insects in fossil resin throughout his career, has several thoughts to share on the copal versus amber controversy. Those who draw distinction between fossil resin, amber and copal are either exhibiting scientific ignorance, and engaging in deliberate obfuscation for financial gain.

Internet sources of information about fossil resin are virtually useless, and are essentially replicating and cross-linking nonsense masquarading as science. One of the most conspicuous examples is the assertion that copal will dissolve in acetone but amber will not. Any chemistry student by their junior year should be able to refute this, or they should not graduate. In reality, fossil resin is a substrate to most solvents. Solubility may, in fact, vary depending on the chemical constituency of different fossil resins, but any statement that solubility determines authenticity is putting the cart before the horse. Another more general falsehood is that age directly correlates with authenticity due to the time required for cross-linking of carbon chains depending on diffusion and loss of terpenes. Yet, Miocene-age coal deposits in Sumatra have yielded resinites that are wholly unstable to environmental exposure. For decades now, sellers of amber from the Baltic region in Europe have stated that the only authentic amber comes from there, and sellers of amber from both the Baltic and Dominican Republic have said that fossil resin from Colombia is not authentic amber. This self-serving disinformation will become truth when swiss chocolate is not chocolote because it does not come from Hershey, Pennsylvannia.

One of dumbest statements to be found on several Internet sites is: "But amber is a true fossil; it has turned to stone"; yea sure it has. Such a transformation would be infinitely harder than turning lead into gold. I wonder who was dumber, the person who copied and pasted it, or the person who wrote it in the first place.

For decades, the suppliers of abundant fossil resin from the Baltic and Dominican Republican operated in a cartel-like manner, controlling the sources, and sustaining prices well above intrinsic value. The Internet age of global communication and resultant supply chains broke the cartel. Amber from these sources can now be obtained at a fraction of the price of years past.


Anderson KB, Crelling JC. (1994) Amber, resinite, and fossil resins. ACS symposium series (A.C.S. symp. ser.) ISSN 0097-6156
Cano RJ, Borucki MK. Revival and identification of bacterial spores in 25- to 40-million-year-old Dominican amber. Science. 1995 May 19;268(5213):1060-4.
Kasman LM, Lukowiak AA, Garczynski SF, McNall RJ, Youngman P, Adang MJ. Phage display of a biologically active Bacillus thuringiensis toxin. Appl Environ Microbiol. 1998 Aug;64(8):2995-3003.
Cano RJ, Poinar HN, Pieniazek NJ, Acra A, Poinar GO Jr. Amplification and sequencing of DNA from a 120-135-million-year-old weevil.