FMF - Friends of Minerals Forum, discussion and message board

[shansen]

Where does amber come from. I think it comes from a tree? If so, what kind of a tree, or does that matter?

[alfredo]

Came from a tree that has been dead for millions of years! If the tree is still alive, it isn't amber, just resin.

[shansen]

[Maxilos]

In fact is is just resin, yes. The mosquito or beatle in it was trapped: it landed on the three, there came resin out of the three and the mosquito or beatle is stuck.

[alfredo]

Not exactly in answer to Shansen's question, but this thread gives me an opportunity to vent about one of my pet peeves: the large quantities of tree resin being sold at mineral shows as "amber". There is a clear distinction between fresh tree resin and amber. Amber is resin which has lost its volatile fraction, and the non-volatile part has polymerized until it becomes relatively insoluble in organic solvents. This takes a VERY long time - hundreds of thousands of years at least, perhaps millions.

The amber from the Baltic region, Dominican Republic, Burma, Chiapas (Mexico), New Jersey, Lebanon, Kuji (Japan) and other geologically old deposits (Cretaceous and Tertiary) is indeed real amber. But nowadays most of the stuff sold at shows or on E-bay, especially the large clear lumps full of insects, comes from Madagascar and Columbia. It is NOT amber. The trees that produced it are not of Tertiary age, nor even Pleistocene - They are still alive! We are talking here about ordinary dried tree resin, a few decades old. When confronted with these facts, the sellers justify the scam by calling it "copal" or "young amber". This is like labelling a bottle of milk as "young cheese" or a pile of grapes as "young wine".

[Ed Huskinson]

"Young cheese".. "Young wine". You crack me up, Alfredo!!! Keep up the good work

Ed

[Elise]

[alfredo]

I agree with Elise that the amount of time required for resin to change into amber must vary greatly. Species of tree that produced the resin, and temperature of the environment must be two important variables, but there are probably a lot of other variables too. I doubt that it would ever happen quickly enough under any circumstances for Holocene resin to become amber. But I might be wrong (my wife says I'm wrong about most things).

[Elise]

Hi Alfredo,
I should clarify (no pun intended) that the heating/autoclaving doesn't turn the copal into amber, merely that the treatment can turn some types of copal into clear, vibrant green stuff which also has slightly different properties than the original material. My understanding from literature is that some types of amber can also be treated the same way to obtain a similar green effect. Maggie indicated that the autoclaving is repeated sometimes many times until the color develops and that it is not always consistent or successful. I am pretty sure she said some of the copal was 200 years old...but I often misplace a zero here and there; I'll ask her now that I am scratching my head about what I thought she said. I wouldn't think that resin would have time to polymerize into "copal" in that brief span; but as you say there are many variables working in concert.
Cheers!
Elise

[alfredo]

Elise, I was only referring to natural amber, not the treated stuff (which I've never seen).

If someone has found a way to use autoclaving to clarify copal, that product should probably be labelled "synthetic" anyway, rather than "treated".

[dmg]

Hello, Yes, different ambers do come from different trees, the two best known ambers, Baltic and Dominican are good examples.
Dominican amber comes from the Algarrobo tree, which grew and still grows in tropical climates, whilst the Baltic amber comes from a type of Araucaria ( commonly known as a monkey puzzle tree) which grew in colder climates.

The chemical changes from copal to amber are quite complex, but invlove the loss of the volatile parts of the resin, which hardens to be come amber. There has been much debate as to what the most important factors in this change are, and it may be that the chemical conditions in the ground, and things such as transportation of the resin play a bigger part in the change than simply time. Although, time is still a very important factor.

Much of what is seen on ebay and at mineral shows, is in fact Copal, in europe we see a lot of copal from Madagascar, but copal from Columbia is becoming more commonly seen. However, there is genuine amber than comes from Columbia, that has been dated at around 23 million years old.

One story surrounding copal from Columbia, with regards to the colour and insect inclusions is that after melting the copal and adding insects to the naturally colourless copal, it is then reburied in a loamy area of soil, and after leaving for a relatively short time ( months / years ??) the colour changes from almost colourless to a more amber like colour. Again showing that chemical conditions, rahter than just time play a role ( this material is still only copal though). This has led to some dealers who have visited Columbia coming back with pieces of copal full of insects and lizzards, stating it must be real, as they saw it being dug from the ground !

I have myself experimented with Columbian material, and there are major differences, using a small rotating grinding tool, as the tool grinds against amber, it gives off a fine dust, whilst with copal, the copal melts and clogs up the tool.

Hope this helps, I have tried to simplify it, but am happy to go into details if anyone is interested

[alfredo]

I would like to know the definition of "copal". To me, as far as I understand it, the resin from Madagascar and Colombia is just that - almost fresh resin; it doesn't merit the term "copal". We could discuss this further if we had some good definitions of the terms but, in the absence of a good definition, we might be crossing our wires.

I have a reasonably clear idea about the boundary between resin and amber, but not between resin and "copal".

It may be true that soil chemistry can affect the outcome, but I'm still a bit dubious about that, because amber is non-porous and water-repellant, so i wouldn't expect pH or soil salts to affect the interior; perhaps the outer crust only? Perhaps organic molecules in the soil can diffuse through it?

[dmg]

Hello Alfredo,
As far as I understand, there is no precise definition of the word coapl ( although its origins are from a South American term for fresh resin)

The Madagascan material is a problem, as it is often said to be 1 or even more million years old. I have however seen reports that claim an age of 500 years or less for the resin itself, and much less for the inclusions ( modern insects inserted into melted resin)

My understanding ( although my studeis are 4 or 5 years behind the times !) is that resin is fresh material ( in a semi sold state) from the tree, as this material starts the process of polymerisation, it starts to harden ( as the volatile oils are lost) the term Copal can then be applied. Amber is the fully hardened polymerised material ( some sources quote a minimum of 20 million years for the completion of this process)

Sub fossil resins as young as 250 years are considered by some as Copal.

I will post again with more information on chemical conditions during the process, as I would like to check my notes before quoting ( a long time since I really looked at the Chemistry, as my main interest is in the inclusions)

From what I can remeber, during the stages of polymerisation, an anaerobic environment is important, as oxygem would cause the resin /copal to oxidise, which would in effect destroy the material. Even fully formed amber still continues to oxidise when exposed to the air ( ie oxygen) This can be sen in many old pieces of amber jewellery, which oxidises and turns red. Pieces of amber jewellery ( say 100 years old) will although only be red on the surface, the red coulour does not go deep into the piece. However, I have the chance to handle pieces that were worked during the neolithic, that were damaged recently ( dropped in a museum) and the colour change had gone all of the way through the piece ( at a thickness of about an inch) ( this of course assumes the amber was not red to start with)

[alfredo]

The hardening process involves at least 2 steps: first, losing the volatiles (which can happen in months to a very few years and will be very temperature-dependant; and secondly polymerisation, which is the part that takes "forever". Evaporation of volatiles by itself isn't going to produce polymerisation. In other words, a dried out resin without volatiles can be made sticky or even liquid again just by adding an organic solvent (like acetone, gasoline or fingernail polish remover). But after polymerisation, ie real amber, one can no longer make it liquid, plastic or sticky with a drop of gasoline.

Red amber may well be red from the beginning, like the ancient stuff from Burma (burmite"). Very old (Cretaceous) amber from Japan, for example, is still light yellow to light brown or whitish, not red. Colour might depend on the type of tree it came from, or temperatures reached in the deposit, rather than the age? ....so much I still don't know about amber!

[Tom Tucker]

Does anyone know the true nature of the "amber" from the Tertiary age coal beds, near Sheridan, Wyoming ? Tom

[alfredo]

Well, if it's from Tertiary coal, then it must be amber, and not resin/copal.

[Elise]

[Pete Modreski]

[Elise]

Hi,

Thank you Pete -- I was interested in Alfredo's concern regarding definitions and dmg's insights - It was just a timely subject in terms of my own research into the problems surrounding environmental controls for displaying amber specimens for the public. I've been corresponding with several curators about how to safely handle amber - closed environments, chemical humidity controls (for organics), horror stories about collections disintegrating. As with mineral collections, insights from private collectors can only widen the knowledge base. And as Alfredo pointed out, without a good definition, or one that people agree on, it makes life harder. I don't know if FMF membership includes many other people collecting amber (jump in here anytime Mark), or whether it even belongs in your forum....I thought for sure someone would pick up on my quotation above of Chhibber in which he called amber a mineral.....and run with it.

I took the question of "copal" as a homework assignment that had me digging through everything from my ratty copy of the 1993 Smithsonian cover story on amber to many books and journal articles relating to the subject. I came away with the feeling that I'd walked into a historical hotbed of semantics while having a small walk-about in etymology regarding terminology for resins. I didn't know that at one time the attempt was made to limit "amber" only to Baltic succinite..."true amber." (Weitschat and Wichard, Atlas of Plants and Animals in Baltic Amber).

Andrew Ross, curator of fossil arthropods at the Natural History Museum, London, wrote in "Amber: the Natural Time Capsule" (which has a nice dichotomous key for inclusions) that most believe the polymerization of resin to amber is dependent on time, but pointed out that "types of sediment in which the resin is deposited is much more important than time for amber formation. ...what is not so clear is the effect of water and sediment chemistry on the resin." (this was in reference to resin in sandstone vs that in clay beds). He describes resin fresh out of the tree as merely hardened resin which then starts to polymerize when it is buried in sediments; "copal" is between "hardened resin" and completely polymerized inert "amber." (but is that process really complete?)

Dahlström and Brost in "The Amber Book" have a detailed chapter titled "A stone or not a stone? a matter of semantics" which goes into the history of all the terms related to amber/resin/copal. Later in the book there is discussion of copal - "hardened resin" which "may be millions, thousands or merely hundreds of years old....One of the oldest kinds of copal comes from Mizunami in Japan" (330,000 years). I don't find other reference to copal millions of years old in that text; perhaps that is an error. They also point out that in Germany resin products under 20 million years old can't be sold as amber, though in the authors' country (Sweden), there isn't a formal regulation regarding age (1996).

In The American Museum of Natural History book "Amber Window to the Past" by David Grimaldi, a section titled "Copal" starts a paragraph with "confusion surrounds the use of the term copal..." It also points out that the oldest copal deposit is that of Mizunami, but gives its age as 33,000 years. The term "resinite" is given as one which geologists use to for "any hardened resin, whether amber or copal"....sounding closely to "retinites" defined in Weitschat as all other fossilized resins other than Baltic succinite. A reference is made to East African copal which "may be 2 million years old, but this is very unlikely." (no citation, but perhaps a lead to the reference Maggie made which I haven't asked her about yet). Just as an aside to the age of Burmese amber, D.A. Grimaldi is one of the people who has published research which updates Chhibber's report of the 30's amber fields - both are widely quoted in other publications, not necessarily together and maybe confusing some.

Dr. Rice in Amber The Golden Gem of the Ages, talks about "true copal" as semi-fossilized resin ranging from "over 1,000 years to as little as 100 years old" (fresh gum from a tree is "raw copal" ). She quotes George Poiner's (Life in Amber) definition of copal "a recently deposited resin that can be distinguished from amber....by its physical characteristics...including hardness, specific gravity, melting point and solubility." and she further states from him "that deposits younger than Tertiary Period (or less than 2 million years old) fall into the copal category."

Along with other passages in books and papers, it seems there isn't much agreement about age. But somewhere back in all that reading, along with several models for visualizing the continuum and agreement that the polymerization process has a lot of variables, I ran across such statements as: "copal" is younger than 1 million years (or "amber" is older than...); amber can be attacked with sulfuric ether and other solvents with difficulty (as opposed to copal which is readily attacked) and that amber isn't completely inert after all. I only referenced readily available books that people may run across. There is much in the scientific literature, for example a nice discussion covering the chemistry and structure of amber vs copal included as an appendix to a paper on green amber by Ahmadjan Abduriyim et al (Gems & Gemology, F09); the whole series of papers by Ken B. Anderson titled “The nature and fate of natural resins in the geosphere” and any of the papers by David Grimaldi, to mention just a few - but still some disagreement.

All that is to say, I can't find a good definition of "copal" and maybe even "amber" is a bit vague.

Cheers!
Elise

[Pete Modreski]

Thanks again for all the comments, Elise. I'm going to be sure to read that article & summary about "resinite" in the F09 Gems & Gemology that you referred to.

This has ever (What is amber?) been a very confusing subject, to I think just about everyone who has ever tried to read about it. I once heard a talk on amber by a USGS staff member (a part-time volunteer actually, who'd been studied this as a side interest) who been doing some chemical studies on amber; I must say, his talk left me, and probably most of the audience, more confused than when he'd begun.

I believe that some "authoritiative sources" say that "true amber" only came from a certain type of tree, that grew in the Baltic region, and that other resins, from elsewhere in the world from other (related, but not the same) species or genera, just are not the same and are not real amber. (I know I'm oversimplifying this, to say it this way.) Perhaps, there are some semantics involved in the definition of "amber".

I'd say that most people in this Forum "pretty much" would accept amber as a valid topic for discussion--even if, of course, it isn't a proper "mineral" in the strict sense.

Pete