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
>
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> Dr. Elizabeth Moore
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> Virginia Museum of Natural History
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