[Nhcoll-l] freezing amber

[Paul Nash]

Hi Jean,

Freezing amber is a bad idea.  Amber pieces often contain bubbles of liquid.  Because water expands when frozen, freezing and thawing amber will likely crack and damage pieces along with their arthropod inclusions. It is even possible for inclusions themselves to contain liquid. And due to the chemical nature of fossil resins (as natural polymers), freezing and thawing could have other deleterious effects. In fact, it is a general rule that significant temperature fluctuations will compromise amber specimens over time.

I've attached a paper on deterioration in fossil resins that addresses conservation protocols. Hope this helps, and please feel free to contact me if you have further questions.

Regards, Paul


 
P.C. Nascimbene 
Paleoentomological Research and Collections
Division of Invertebrate Zoology 
American Museum of Natural History
79th Street at Central Park West
New York, NY 10024      USA


________________________________
 From: "Demouthe, Jean" <JDemouthe at calacademy.org>
To: "nhcoll-l at mailman.yale.edu" <nhcoll-l at mailman.yale.edu> 
Sent: Friday, March 28, 2014 2:24 PM
Subject: [Nhcoll-l] freezing amber
 


 
Dear Colleagues:
 
Most of our amber is held by the Entomology department, who freeze everything before putting it in the collection room.  Every time anything goes out, it gets refrozen.
 
I am looking for information or references on the effects of freezing and/or repeated freezing on amber.
 
Assume the conditions are:  48 hours at <0o C.
 
Any help you can give me will be greatly appreciated.
 
Jean 
 
 
 
 
Dr. Jean F. DeMouthe
Senior Collections Manager for Geology
California Academy of Sciences
55 Music Concourse Drive
San Francisco, California 94118
415-379-5258
jdemouthe at calacademy.org
 
_______________________________________________
Nhcoll-l mailing list
Nhcoll-l at mailman.yale.edu
http://mailman.yale.edu/mailman/listinfo/nhcoll-l

_______________________________________________ 
NHCOLL-L is brought to you by the Society for the Preservation of
Natural History Collections (SPNHC), an international society whose
mission is to improve the preservation, conservation and management of
natural history collections to ensure their continuing value to
society. See http://www.spnhc.org for membership information.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.yale.edu/pipermail/nhcoll-l/attachments/20140328/14624516/attachment-0001.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Variation in the Deterioration of Fossil Resins	and Implications for the Conservation of Fossils in Amber.2012	- nascimbene.pdf
Type: application/pdf
Size: 602359 bytes
Desc: not available
Url : http://mailman.yale.edu/pipermail/nhcoll-l/attachments/20140328/14624516/attachment-0001.pdf