[Bonetools] Colouring bone

Wed Apr 16 17:58:11 CEST 2014

Thank you Ian, that sorts out tonight’s reading material.

Regards,

David Constantine

From: Ian Riddler 
Sent: Wednesday, April 16, 2014 4:42 PM
To: Mailing list for archaeologists of the research group for the study of object and waste of bone, antler. ivory and horn. 
Subject: Re: [Bonetools] Colouring bone

Hello Dave,

This is an old text about object technology, which I’m going to revive and publish soon, and it includes a few examples of coloured objects on pages 16-17, a few of which are Anglo-Saxon. More merovingian examples too: is that actually because people are looking harder for these things nowadays, or were merovingian combs painted or stained more than combs from elsewhere ?

Ian Riddler

From: Dave Constantine 
Sent: Wednesday, April 16, 2014 4:15 PM
To: Mailing list for archaeologists of the research group for the study of object and waste of bone, antler. ivory and horn. 
Subject: Re: [Bonetools] Colouring bone

Thank you all for your replies. 

Vincent, the green stained comb you linked is rather interesting. Do you know what the green pigment is? Also, looking at the images, it seems that it is no more than a surface colourant with little penetration, is this correct? 

Thank you for your suggestion of minium, I was at a loss about what it could be. It is not a fresh find, it was originally discovered in the 1960s (or possibly 1970s) and mounted on a card for display. To the best of my knowledge though, the colouring is original, though it is possible that the surface was also coloured and this has simply failed to survive.

I have Arthur MacGregor’s book, and very useful it is too on the matter of colouring. 

Regards,

David Constantine

From: Vincent Cattersel 
Sent: Wednesday, April 16, 2014 2:03 PM
To: Mailing list for archaeologists of the research group for the study of object and waste of bone, antler. ivory and horn. 
Subject: Re: [Bonetools] Colouring bone

Dear all, 

this is a first where I might be able to contribute to this group, but I'm happy to do so:

In 2008 I have conserved and restored 8 bone/antler combs from the Merovingian period at the Royal Institute for Cultural Heritage (Brussels, Belgium). These combs are currently preserved at the Royal Museums of Art and History in Brussels, Belgium.
Here you can find pictures of a few of them (click on the pictures to get a zoomable high resolution image):
http://balat.kikirpa.be/photo.php?path=X026849&objnr=20042741

http://balat.kikirpa.be/photo.php?path=X035781&objnr=20052916 (green staining on the surface, carbon black in the circular motives)

http://balat.kikirpa.be/photo.php?path=X026845&objnr=20052917

http://balat.kikirpa.be/photo.php?path=X038388&objnr=20052919

http://balat.kikirpa.be/photo.php?path=X035783&objnr=20052922

Some of these where coloured and stained with green and carbon black. We used µ-XRF, µ-RAMAN and SEM(-EDX) to analyse the stains and the carbon black particles.

So staining and colouring isn't that uncommon, as you probably already know.

When I look at the picture, I can see that the red is slightly orange, which makes me think about the pigment lead red (also called 'minium' or lead tetra-oxide, Pb3O4). This isn't a surprise since it is one of the oldest known vivid red pigments (except for some iron oxide pigments derived from hematite and red earth or cinnabar (HgS), however they all are true 'reddish' in colour and lack the hint of orange). 

Some simple identification techniques for minium are: 
  a.. Ultraviolet fluorescence (if minium, it minium it should show a dark red colouration);

  b.. Infrared False Color which should gives the observed minium a yellow-brown colour. 
Analytical techniques:
In case you have the oppurtunity to analyse it with RAMAN, you can find a reference spectrum here.
For a reference spectrum of minium using XRF: here.

Another thing is the question whether this die was excavated and brought directly to your collection or was it once part of a (private)collection and excavated a long time ago. 
This is an important question since it could provide an answer to whether or not this colouration is original.
I know from my experiences with the conservation of precious ivory objects that they are often repainted (repolychromed) throughout time, even though their iconography or typology gives us reasons to believe that they originally weren't polychromed or not polychromed in such manner as they are today. 

To get back on the minium pigment, more information can be found in:
  a.. Eastaugh, N., Walsh, V., Chaplin, T., & Siddall, R. (2008). Pigment Compendium - A Dictionary and Optical Microscopy of Historical Pigments. Oxford: Butterworth-Heinemann.

  b.. Feller, R. L., Gettens, R. J., & Chase, W. T. (1993). Vermilion and Cinnabar. In R. Ashok, Artists' Pigments - A Handbook of Their History and Characteristics. (Vol. II, pp. 159-182). Washington-London: National Gallery of Art. 

Another book I can recommend on staining and colouring bone materials is: McGregor. A. (1985) Bone, Antler, Ivory & Horn: The Technology of Skeletal Materials Since the Roman Period. 
I don't have it here with me for the moment, but as you wish, I can always go through it to find more information on red staining or colouring. 

Yours,

Vincent Cattersel

Drs. VINCENT CATTERSEL
Doctoral researcher
Universiteit Antwerpen / University of Antwerp
Faculteit Ontwerpwetenschappen / Faculty of Design Sciences
Opleiding conservatie-restauratie / Conservation Studies
Blindestraat 9
B-2000 Antwerpen
T +32 3 213 71 34 | F +32 3 213 71 35
vincent.cattersel at uantwerpen.be
www.uantwerpen.be

On 15 April 2014 09:06, David Constantine <dkconstantine at btinternet.com> wrote:

  Hello All, 

  Attached is an image of a (probably) Saxon bone/antler die. As can be seen, there is reddish pigmentation in the decoration. I have looked around for similar colouring and with the exception of a "lucet" from London I cannot seem to find anything similar, just totally stained objects e.g. the belt buckle from York. Does anyone here know of any Early Medieval dated bone artefacts that are either entirely stained/dyed or have coloured decoration such as this?

  Regards,

  David Constantine

  _______________________________________________
  Bonetools mailing list
  Bonetools at listserv.niif.hu
  https://listserv.niif.hu/mailman/listinfo/bonetools

--------------------------------------------------------------------------------
_______________________________________________
Bonetools mailing list
Bonetools at listserv.niif.hu
https://listserv.niif.hu/mailman/listinfo/bonetools

--------------------------------------------------------------------------------
_______________________________________________
Bonetools mailing list
Bonetools at listserv.niif.hu
https://listserv.niif.hu/mailman/listinfo/bonetools

--------------------------------------------------------------------------------
_______________________________________________
Bonetools mailing list
Bonetools at listserv.niif.hu
https://listserv.niif.hu/mailman/listinfo/bonetools
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://listserv.niif.hu/pipermail/bonetools/attachments/20140416/c73bd8cf/attachment.html>