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Re: Identifying amber




>
>I was recently given a chunk of what appears to be amber or hard rosin
>measuring about 10 cm by 5 cm by 3cm. Does anyone have any suggestions
>on how I might identify it? I thought that someone in this group might
>have knowledge on this.
>
>Many Thanks!
>Casey Burns
>casey_burns@tscnet.eskimo.com
>
>
Garry Platt uploaded a terrific article on this subject some time ago. I 
don't know if you received responses to your question via personal 
e-mail, but for the benefit of all the newbies on the dino list, I am re- 
posting it to the list. It's a keeper....


Begin>>>

Date: Tue May 17 03:16:06 1994
From: garry@gplatt.demon.co.uk (Garry Platt)
Subject: Identifying True Amber (Succinite)


Identifying True Amber (Succinite)

Since the screening of 'Jurassic Park' interest in the mineral Amber has
grown significantly. Unfortunately so has the quantity of fake Amber coming
on to the market. Some of these pieces have insect inclusions skilfully
placed in the body of the material.

The British Natural History Museum recently discovered that a bee preserved
in Amber thought to be the oldest known example of this particular species
was in fact a fake and probably no more than 150 years old. (More of this
bee later). Evidence of this nature, that even the best can be fooled
should alert all collectors to the possibility of being misled or simply
cheated.

In some cases Copal, which is tree rosin which has not yet fully fossilised
to Amber and may be anything up 3-4 million years old is described as true
Amber. 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.

There are a number of simple tests which can be carried out on Amber to
check its authenticity. I have listed here all these basic methods I have
come across. More sophisticated and complex tests are possible but they
require access to laboratory equipment. These more complex tests include:
Refraction Index, Polarized Light test for Ambroid (Conglomerated and
Pressed) Amber, Specific Gravity, Melting Point.

When examining a specimen you should try at least 3 of the following
methods detailed here. If the item in question fails any one of the tests,
it could well mean the piece is not true Amber.

(Test 1) HARDNESS.

Amber has a hardness on scale of 2 - 3 using Moh's scale. Using appropriate
scratch sticks it should be reasonably straightforward to test the sample
under question.

(Test 2) HOT NEEDLE.

Heat a needle point in a flame and then push the point into the sample for
testing. With Copal the needle melts the material quicker than Amber and
omits a light fragrant odour. Amber when tested does not melt as quickly as
the Copal and omits sooty fumes.

(Test 3) SOLUBILITY.

Copal will dissolve in acetone. This test can be done by dispensing the
acetone from an eye dropper onto a clean surface of the test specimen.
Amber will however remain unaffected by contact with Acetone.

(Test 4) UV

Copal under a shortwave UV light shows hardly any colour change. Amber
fluoresces a very pale shade of blue.

(Test 5) FRICTION

Rub the specimen vigourously on a soft cloth. True amber may omit a faint
resinous fragrance but Copal may actual begin to soften and the surface
become sticky.

(Test 6) TASTE

This test was introduced to me by a Antique Trader who specialised in Amber
beads. She explained that one of the most reliable tests she used was to
taste the Amber specimen after washing it in mild soapy water and then
plain water. Whilst she could make no distinction between Copal and Amber,
she could easily identify Plastics and other common substitutes because of
their unpleasant or chemical taste. Amber has hardly any taste at all. As a
method for identification I have not seen this procedure recorded
elsewhere. I can vouch for its effectiveness as a not destructive method of
differentiating between Amber and certain other substances often
misleadingly labled Amber.


Anyone wishing to find out more about AMber in general or these test
methods specificaly would do well to consult one of two books currently
available on Amber, they are:

Life In Amber
George O. Poinar, Jr.
Stanford University Press
ISBN: 0-8047-2001-0

and

Amber - The Golden Gem of the Ages
Patty C. Rice,
The Kosciuszko Foundation, Inc
ISBN: 0-917-00720-5

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 Douglas E. Goudie                  To know all things is not permitted.
 ac941@leo.nmc.edu                               -- Horace (65 - 8 B.C.)