[Nhcoll-l] vivianite preservation

Tue Apr 24 04:57:49 EDT 2018

Hi Becky,

What is more important to preserve, the waterlogged wood or the vivianite?

Vivianite is an iron-phosphate mineral often associated with archaeological objects (i.e. waterlogged wood and skeletons), as it can form from the oxidation of pyrite and in association with phosphate-rich minerals (e.g. bone). Vivianite is originally clear but oxidises quickly and then turns blue. It also contains 8 molecules of crystalline water per molecule of mineral, and is therefore prone to dehydration. If waterlogged wood (which itself is preserved because it would have been buried in an anoxic environment) is exposed to the atmosphere, the oxidation and associated colour change in vivianite can happen quite quickly. Dehydration of vivianite can result in cracking and physical disintegration.

To preserve the vivianite you would need to contain it in a micro environment under high relative humidity and exclusion of oxygen.

If you were more interested in preserving the waterlogged wood, any of the usual ways for doing so (e.g., impregnation, replacement of water with non-aqueous solvents, freeze drying) would be mutually exclusive with the preservation of vivianite.

Kind regards
Christian

Dr Christian Baars AMA
Senior Preventive Conservator
National Museum Cardiff
Department of Collection Services
Cathays Park, Cardiff CF10 4NP, UK
Telephone: +44 (0)29 2057 3302
E-mail: christian.baars at museumwales.ac.uk<mailto:christian.baars at museumwales.ac.uk>
Twitter: @NMWPrevCons
Blog: https://urldefense.proofpoint.com/v2/url?u=http-3A__www.museumwales.ac.uk_blog_-3Fcat-3D2484&d=DwIGaQ&c=cjytLXgP8ixuoHflwc-poQ&r=LpYc_Z_iN1KRw0hheb3x6-8MJUMu482qfHowpGYJqwc&m=PCIrsy3dDUBu0h0xYSJC7E9ZMRrsq4XijIMIZKFFh2I&s=ZRvZOniCKG6lB0Jfm3s_Zdr5vfWAbU-dwrW-8lMPWCA&e=
https://urldefense.proofpoint.com/v2/url?u=https-3A__museum.wales_staff_643_Christian-2DBaars_&d=DwIGaQ&c=cjytLXgP8ixuoHflwc-poQ&r=LpYc_Z_iN1KRw0hheb3x6-8MJUMu482qfHowpGYJqwc&m=PCIrsy3dDUBu0h0xYSJC7E9ZMRrsq4XijIMIZKFFh2I&s=WSe7K17VZFvk8akPXD0jT-uB_gRJXLLs5MssbrjZLyc&e=

From: Nhcoll-l [mailto:nhcoll-l-bounces at mailman.yale.edu] On Behalf Of Becky Desjardins
Sent: 24 April 2018 07:58
To: nhcoll-l at mailman.yale.edu; Arike Gill <arike.gill at naturalis.nl>
Subject: [Nhcoll-l] vivianite preservation

Hello all;

One of our curators recently collected a sample of  waterlogged wood (could be clay) with crystals of vivianite on it. Vivianite changes color when exposed to air (which is already happening) and the wood/clay is drying out. Does anyone have any tips for how to preserve it? Keep it in glycerine? Or oil? I welcome your suggestions.

Met vriendelijke groeten,

Becky Desjardins
Taxidermist/Preparator

[Image removed by sender.]

T 071-751 9252 , M 06-16144902

Darwinweg 2 - 2333 CR Leiden
E Becky.Desjardins at naturalis.nl<mailto:Becky.Desjardins at naturalis.nl> I , www.naturalis.nl<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.naturalis.nl_&d=DwMFaQ&c=cjytLXgP8ixuoHflwc-poQ&r=LpYc_Z_iN1KRw0hheb3x6-8MJUMu482qfHowpGYJqwc&m=9gG_DklWLxsTRW4hBfOVfu37farkF4kFuQi8IKeNO0Y&s=SjnEWfoDPTAf6RfRqX33-beWwzQ3nWO5sTM9_X9FAb0&e=>

Due to the construction of new public museum facilities, depots, labs and offices, the zoological, geological and paleontological collections of Naturalis Biodiversity Center in Leiden will be closed to all visitors, including Synthesys Access applicants, as well as for all loan requests for two months during March and April 2016, and for a period of about two years from August 2016 till summer 2018. The botany collections, housed elsewhere in Leiden, will remain open to visitors and available for loans until further announcement. In case of logistic questions and updates on planning and progress, please check www.naturalis.nl<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.naturalis.nl_&d=DwMFaQ&c=cjytLXgP8ixuoHflwc-poQ&r=LpYc_Z_iN1KRw0hheb3x6-8MJUMu482qfHowpGYJqwc&m=9gG_DklWLxsTRW4hBfOVfu37farkF4kFuQi8IKeNO0Y&s=SjnEWfoDPTAf6RfRqX33-beWwzQ3nWO5sTM9_X9FAb0&e=> or contact collectie at naturalis.nl<mailto:collectie at naturalis.nl>. We apologize for this inconvenience.

YMWADIAD
Rydym yn croesawu gohebiaeth yn Gymraeg a Saesneg, ac yn sicrhau y byddwn yn cyfathrebu â chi yn eich iaith ddewisol, boed yn Gymraeg, Saesneg neu’r ddwy, dim ond i chi ein hysbysu. Ni fydd gohebu yn Gymraeg yn peri oedi.
Mae pob neges e-bost a anfonir at neu gan Amgueddfa Cymru yn cael ei 
sganio gan systemau diogelwch awtomatig. Sganiwyd y neges hon am firysau cyn ei hanfon, ond dylech hefyd wirio bod y neges, a phob atodiad ynddi, yn rhydd o firysau cyn ei defnyddio. Nid ydym yn derbyn cyfrifoldeb am unrhyw golled neu ddifrod o ganlyniad i agor y neges neu unrhyw atodiadau. Gall y neges hon ac unrhyw ffeiliau a atodir ynddi gynnwys gwybodaeth gyfrinachol a fwriadwyd ar gyfer y derbynnydd yn unig. Os ydych chi wedi derbyn y neges trwy gamgymeriad, hysbyswch ni a dileu’r neges. Safbwyntiau personol yr awdur a fynegir yn y neges hon, ac nid ydynt o reidrwydd yn cynrychioli safbwyntiau Amgueddfa Cymru. Nid ydym yn derbyn cyfrifoldeb am unrhyw wallau, llygredd neu esgeulustod a allai godi wrth drosglwyddo'r neges hon.

DISCLAIMER
We welcome correspondence in Welsh and English, and we will ensure that we communicate with you in the language of your choice, whether that’s English, Welsh or both if you let us know which you prefer. Corresponding in Welsh will not lead to any delay.
E-mail to and from Amgueddfa Cymru is scanned by automated security systems. This message was scanned for viruses before transmission, but you should also satisfy yourself that the message, and all attachments, are virus-free before use. We can accept no responsibility for any loss or damage that might arise from opening the message or any attachments. This message and any files transmitted with it may contain confidential information intended only for the recipient. If you receive the message by mistake please inform us and delete it. The views expressed in this message are the personal views of the author and may not necessarily represent those of Amgueddfa Cymru. We accept no liability for any errors, corruption or omissions that might arise in transmission of this message.

--
 Scanned by FuseMail.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.yale.edu/pipermail/nhcoll-l/attachments/20180424/6fee488d/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ~WRD000.jpg
Type: image/jpeg
Size: 823 bytes
Desc: ~WRD000.jpg
URL: <http://mailman.yale.edu/pipermail/nhcoll-l/attachments/20180424/6fee488d/attachment.jpg>