Susanne mentioned seeing more metallic colours on bones as well. I have seen a few cases from anoxic, organic sediments in which the calculus on cattle and sheep teeth has been diagenetically altered to something resembling a complex metal sulphide, such as iron or copper pyrite. Yes, it looks as if the animals have fillings....
Terry O'Connor
Professor of Archaeological Science
Department of Archaeology, University of York
Biology S Block, Heslington,
York YO10 5DD
+44-1943-328619
On 18 July 2012 03:29, Richard Wright
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Elizabeth
I agree with Susanne Miller's suggestion. Colour sounds spot on for vivianite.
Some things to think about.
In my experience, vivianite appears as crystals or powder on the surface of the bone, and is not to be described as 'staining'. In other words, its distribution does not look like the familiar staining of bone in contact with copper or bronze. In saying this, I confess that my experiences with vivianite are not that numerous.
You have to have three local properties for vivianite to form:
1) Phosphate, which is of course obtained from the bone itself.
2) Iron - either from an associated iron artefact or from an inherently iron rich soil.
3) The anaerobic conditions Susanne mentions.
In older archaeological environments, stagnant water-logging of clay will provide suitable anaerobic conditions.
In the forensic context, if bodies are buried en masse in a grave where the soil is clay, then anaerobic conditions are soon provided once the putrefying bacteria have used up the available oxygen. Some victims of the Srebrenica massacre were buried in a secondary grave in October 1995. When we excavated them in June 1998, they had crystals of vivianite on their flesh, bones and clothing.
There is an excellent review of vivianite in archaeological settings by McGowan and Prangnell in Geoarchaeology: an International Journal, Vol 21, No.1, pp.93-111 (2006).
So - I guess the chief property for you to consider, before concluding the colour is vivianite, is whether there were relevant anaerobic conditions (e.g., a cess pit) being excavated at the inn/hotel in question.
Richard Wright
On 18/07/2012 07:09, Moore, Elizabeth (VMNH) wrote:
I have a cow carpal that has been stained bright turquoise (blue green) in color. It does not look like any copper staining I have seen before - it's too blue. It is from an inn/hotel built in the 1850s in south central Pennsylvania (eastern United States). Has anybody ever seen any bright turquoise staining? I don't know what color other metals stain except for copper which is usually more green than this. No hints present from the other artifacts in this context.
Elizabeth
_________________________________________________________________________________________________________
Dr. Elizabeth Moore
Curator of Archaeology
Virginia Museum of Natural History
Martinsville, VA 24112
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