[Jewelry making - Article 00698] - Re: [Orchid] Copal vs. Amber

[Terri May]

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    Hi Andrew -- You take your resinous materials very, very seriously. 

>>         Andrew suggested that "Copal is at most some hundreds of years
>>     old, as opposed to amber which is millions of years old."  This is
>>     not really true.  Copal often is some 500,000 to 1,500,000 years
>>     old or more. 

>     Often? Have you got any authority for that?

    Here's just one example (from a site which you approve, since you
    cited it yourself -- possibly you just didn't read the whole
    thing?): 

    "Copal has been referred to as a subfossil resin, semi-fossilized
    resin, an immature amber, and as a fresh, gum form of resin. Experts
    vary in their assessment of the age of copal, from 50 years to 1.6
    million years, based on the geologic settings in which it is found
    and other evidence, both chemical and botanical." --
    http://www.emporia.edu/earthsci/amber/copal.htm 

    There are numerous citations in books and on the internet from both
    educational institutions and commercial dealers who agree with this
    range of dating, though I've read others which extend the dates to
    earlier times as well. 

>     Yes, it's possible to create a heat-affected zone in amber,
>     especially if you use power tools too enthusiastically, but it
>     won't turn to goo like copal will.

    Andrew, if you are turning your Copal to "goo", are you sure you
    know how to work it properly?  I've never had that problem. 

>>         As a low cost material, Copal amber is a pretty altenative to
>>     the much more expensive Baltic amber.

>     Maybe for a while. But due to its greater volatility, it has a
>     much more pronounced tendency to craze in the presence of oxygen,
>     heat and UV exposure, making it a poor choice for jewelry
>     purposes.

    It can craze or chip, just as Baltic amber can.  Many materials that
    we use in jewelry are fragile in nature in some way or other, like
    emeralds, opals, or white gold (or in "modern" jewelry, feathers or
    paper).  With any reasonable care a copal amber piece can last a
    very long time.  It has existed in nature "from 50 years to 1.6
    million years" (see above quote), so it should outlast even a short
    human lifetime, if cared for properly. 

>>         (Always remember to disclose that it is Copal amber to
>>     whomever purchases your pieces; that keeps everyone happy.) 

>     Don't tell them it's any kind of amber - unless you're the sort of
>     person who sells graphite as "young diamond" ..."

    No, Andrew, I'm the sort of person who likes to be as truthful as
    possible. 

>     Distinguishing between copal and amber is a contentious issue
>     amongst members of the amber community. There is no scaling system
>     for assessing polymerisation against age. This is because too many
>     external factors affect the rate of molecular linking and
>     consequently a variable rate does not lend its self to a linear
>     time assessment system. Because of this the nomenclature of resin,
>     copal and amber is not an absolute science yet." 

    Andrew, I'm happy for you that you research subjects that interest
    you.  And semantics are a wonderful thing to deconstruct when they
    can bring clarity and understanding to a difficult issue.  The
    problem is that the Experts are still disagreeing over this -- so
    unless you consider yourself the difinitive authority on the
    resinous fossil issue, you need to give it a rest. 

--Terri

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