Fossil
Amber or Fossil Resin
Fossil
Resin is the proper terminology for what has commonly been called
amber, and is, as the proper name denotes, fossilized resin
of botanical origin. The common word amber has numerous other
usages, such an orangish-yellow color, a type of ale, a kidnapping
alert system, a version of the Linux operating system, and many,
many more. Fossil resin reflects many frequencies of light,
including red, green and blue, thus spanning the entire visible
spectrum. Archeological findings show that prehistoric humans
used fossil resin for ornamentation as far back as 30,000 years
ago. Use of fossil resin for jewelry and other decoration constitutes
a large industry, and fossil resin is often considered as a
gemstone. However, this consideration is very misleading: while
diamonds are forever, fossil resin is not. Diamonds are extremely
hard and stable crystal structures of tetrahedrally bonded carbon
atoms. Fossil resin, on the other hand, is a highly unstable
polymer consisting of structural units and repeating units connected
by covalent chemical bonds. Both DNA and proteins are also polymers.
Commercial
interests have succeeded in labeling younger fossil resins in
order to ascribe a higher monetary value to older resins. The
term copal is thus used in a derogatory context, but has no
significance based on either chemistry or paleontology. Jewelers
have been trained to draw the distinction, where science sees
none except for the resin’s age and age of fossilized
plants, animals and fungi inclusions.
Amber
is valued for its botanical and animal inclusions that are trapped
by the sticky resin as it flows fulfilling its role in protecting
the plant. 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 scientific value in the study of taxonomy
and evolution. Animal inclusions are usually invertebrates,
specifically arthropods, and only extremely rarely a vertebrate
such as a small lizard. Fossil resin inclusions are overwhelmingly
insects, which naturally follows from the resin’s evolutionary
origin as a physical means of protecting plants from insect
pests.
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 is a "plastic". Just
when the resin becomes amber, or a fossil, is not definable
by any scientific criteria.
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 very small by comparison.
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 available 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 reletively
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 unlikly 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, in Colombia the danger is AK47's.
Whether amber or copal, young or old, the fossil insects and
other arthropod inclusions and their associations are truly
sublime. Perhaps the most impressive aspect of Colombian amber
to those with a scientific propensity are 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
A
few more words about the distinction between amber and copal,
both slang terms without scientific basis, is warranted. It
is fairly widespread on the Internet and several popular and
otherwise wonderful "amber" books that there is
no amber from Colombia, that it is "young" copal,
because it has not yet undergone some magical transformation
that is obfuscated but never described. This is a perfect
example of the old saw: "if you tell a lie enough times,
it becomes (perceptive) reality". 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 traned in science continue
to promulgate scientific popycock. 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.