[Jewelry making - Article 00499] - Re: [Orchid] Copal vs. Amber

[jake]

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    Some basic information on amber can be found at
    http://home.t-online.de/home/Arnold-Heide/lexicon.htm and
    http://www.gemsociety.org/info/gems/Amber.htm - There is more
    information out there. A word of caution, some people have a vested
    interest, so be skeptical, much like natural turquoise is so hard to
    find, not really, they just don't want to pay for it and so invent a 
    rationalization, a "story" actually. Sad to say this sometimes
    applies  to other tings as well. Dominican amber is a case in point,
    there is  amber deposits but much larger copal deposits, non
    processed stones are  most likely copal, as by law they are not to be
    exported. 

    Best acetone test: Place one drop on the surface of the test piece
    and  allow it to evaporate, then place a second drop on the same
    area. Copal  will become tacky; amber will remain unaffected by
    contact with acetone.  

    Alcohol testing is said by some to be biased as you may get a false 
    result on non-Baltic amber, such as Lebanon, Burma, Dominican, and 
    Sicilian, New Jersey, etc., etc., etc. Other types came from
    different  trees and is not the same chemically, so this may not be
    a good test,  unless it is said to be Baltic. 

    As for Colombian, there is material from Santander, this has some 
    non-copal qualities. However this is not accepted as amber and doesn
    92t  meet all qualifications. To sell it as amber could cause
    problems, at  least if you ever wanted to be taken seriously as a
    professional, the  stuff is great for wire wrapping, just tell them
    what it is. I do not  sell any or have I, nor do I think I will, but
    I wonder if Santander  should be differentiated to set it apart from
    other copal. To those who  repeat that (all) Colombian copal is only
    a few hundred to (at most) a  few thousand years old, this is taken
    from someone who it is said never  tested the Santander material. In
    any event according to Geologists the  deposits were laid down
    between 1 and 2 million years ago, and some  perhaps 3, I will
    believe them on this, as they have no interest. 

    I will use excerpts from Identifying True Amber. "In some cases
    copal,  which is tree resin which has not yet fully fossilized to
    amber and may  be anything up 3-4 million years" 85. "Debate still
    rages in the UK  about certain Kenyan deposits as to whether they
    should be called copal  or amber and I have heard of similar
    arguments concerning deposits found  in South America." (This last
    is a reference to the Santander material  mentioned above.) 

    This last is interesting; there exists copal old enough to be amber.
    But  is not. We do not yet know just what turns copal to amber, some
    have  suggested some conditions but we really do not know. Do you
    know that  some copal (a small amount) comes from the Baltic? We are
    all told that  green shades of turquoise have iron, this is true.
    However Persian  turquoise often used as the standard has a higher
    iron trace than  others, and this is obviously blue, so we still do
    not know everything. 

    I read on this list a suggestion that you could tell amber from
    copal as  it is darker. This is wrong. Below is from a cutting hose,
    realize that  this has been going on since the ice age. And although
    this is treated  the same thing happens naturally, spangles (blitz)
    occur naturally, but  it is almost certain to have been man induced,
    as is much of the "amber"  coloring. I have seen a photo taken in
    the 60s of Bitterfield amber in  large piles stored outside in the
    sun over time to "cure" it, this dose  some of the same. 

    "Most of the natural rough stones are milky, pale or translucent but
     very light yellow. To match the taste and the requirement of the 
    consumers, a very special technique of heat treatment for these
    stones  has been developed, whereas each company, working with these
    fine  stones, keeps their developed technique as a secret part of
    know-how for  themselves. Just by heating these stones (at low
    temperature), the  following general changes will appear: If heat
    and air (as in a regular  stove is the case) is supplied to the
    stones, the material will clear up  and darken. If stones are heated
    under vacuum (i.e. by an autoclave),  stones will clear but not
    changing their color to a darker shade. By  special techniques, heat
    may cause the "Glitter" to appear inside of the  stone. Properties
    of the gem do not change at all, so that such a heat  treatment to
    Amber may never be proofed and the stone still to be  considered as
    natural Amber." 

    (Natural conditions can also cause the same changes; no test can
    differentiate the two. Archeologists have found evidence of people 
    treating amber some 14,000 years ago.) 


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