Hi all,
Several Histarch members asked me to keep them updated on the progress  
toward developing the newly-proposed "fired-clay ceramic  
rehydroxylation dating method" (RHX dating).

Two articles have been published in 2010 and 2011 of interest.

First:
Tosheva, Lubomira; Mihailova, Boriana; Wilson, Moira A.; and Carter,  
Margaret A. (2010) Gravimetric and spectroscopic studies of the  
chemical combination of moisture by as-fired and reheated terracotta.  
Journal of the European Ceramic Society 30:1867-1872
http://www.mace.manchester.ac.uk/research/publicationAbstract/journal_pdfdownload.php?id=2497

In this paper, the authors further refine the proposed RHX technique.   
They plot additional experiments with a sample brick, for which they  
plotted the fractional mass gain against their time (1/4) power law.   
The smoothly curved plots again show the great deal of promise- there  
seems to be little error in the process as this group has worked  
things out.

Second, our first collaborative experiments at Michigan Tech have also  
been published and are now available in preview:

Bowen, P. K., Ranck, H. J., Scarlett, T. J. and Drelich, J. W. (2011),  
Rehydration/Rehydroxylation Kinetics of Reheated XIX-Century Davenport  
(Utah) Ceramic. Journal of the American Ceramic Society, 94: no. doi:  
10.1111/j.1551-2916.2011.04451.x
http://onlinelibrary.wiley.com/doi/10.1111/j.1551-2916.2011.04451.x/abstract

Abstract
Rehydroxylation (RHX) dating has recently been proposed as a new  
chronometric dating tool for use on archeological fired-clay ceramics.  
The technique relies upon the well-known characteristic of reheated  
porous ceramic vessels to regain water through a two-stage process  
(rehydration and RHX), where the kinetics of second stage has been  
shown to follow a (time)1/4 power law at temperatures of 13°–50°C. In  
this study, experiments were conducted in which the mass measurements  
taken from 19th-century ceramic artifacts could be described by the  
(time)1/n power law over a wide range of temperatures. This finding  
has led to the formulation of a new empirical equation, which  
describes the observed ceramic's rehydration and RHX behavior without  
the need for identification of RHX stage. As part of this study, the  
mineralogy of the ceramics and their thermal properties have been  
evaluated. The instantaneous effect of humidity on mass measurements  
was demonstrated to be the principal source of error. RHX dating shows  
promise, and after more research, the technique could become an  
important archeometric tool.

Our experiments, based upon the 2009 experiments by Wilson et al, also  
showed promise for the technique.  The materials scientist and  
students with whom I collaborated developed an expanded equation that  
describes the process of both rehydration and rehydroxylation, because  
they were unconvinced that the "stage I" rehydration process could be  
left out of the model.  We also expressed some concern about the  
effects of minerology.  I would not say that any of our findings are  
definitive, however.

We are eagerly awaiting the results of our NSF proposal.  Hopefully,  
will will be able to get some new equipment and continue the work.

Cheers,
Tim



The original research team has been working on this for about 10  
years, culminating in the 2009 article:
Wilson MA, Hoff WD, Hall C, McKay B, Holey A. Kinetics of moisture  
expansion in fired clay ceramics: a (time)1/4 law. Phys Rev Lett  
2003;90:125503-1–4.
Savage SD, Wilson MA, Carter MA, Hoff WD, Hall C, McKay B. Moisture  
expansion and mass gain in fired clay ceramics: a two-stage (time)1/4  
process. J Phys D: Appl Phys 2008;41:055402.
Wilson MA, Carter MA, Hall C, HoffWD, Ince C, Savage SD, McKay B,  
Betts IM. Dating fired-clay ceramics using long-term power law  
rehydroxylation kinetics. Proc R Soc A 2009;465:2407–15.


-----------------------------------------------------------------
 From the Histarch Archive:

-----Original Message-----
From: scarlett <[log in to unmask]>
To: HISTARCH <[log in to unmask]>
Sent: Thu, Jan 13, 2011 7:02 am
Subject: Re: Food for Thought: A New Way to Date Old Ceramics


Hi Tim,

There are three other teams around the world working to replicate the
initial results of Wilson et al., including two in the US and one in
Israel.  These are those of which I am aware. The problems right now
are not access to samples.  We are all still trying to work out some
of the basic science around this proposed technique.  The initial
experiments we did here at Michigan Tech were promising, really very
promising, but much more work needs to be done before anyone can offer
this a useful tool.

I understand the enthusiasm and interest, and I'm sure Dr. Wilson and
her team appreciate all the emails they received offering samples.
Everyone will have to be patient while we see if we can reach a
consensus on lab methods, sample selection, and all the other dirty
details.  That will take time and money to get the basic scientific
studies finished and published.

Dr. Wilson did an interview with the RSA in the UK which they have
posted on-line at their website:
http://www.datingceramic.manchester.ac.uk/

Cheers
Tim


On Jan 13, 2011, at 2:52 PM, Timothy K. Perttula wrote:

 > There were 2 articles published on rehydroxylation as a dating
 > method in 2003 (Kinetics of Moisture Expansion in Fired Clay
 > Ceramics: A (Time)1/4 Law), in Physical Review Letters 90(12) by
 > Moira A. Wilson et al.; and 2009 (Dating fired-clay ceramics using
 > long-term power law rehydroxylation kinetics), in Proceedings of the
 > Royal Society A, by Moira A. Wilson et al..
 >
 >
 > Sounds like great promise, but other than the few mentions of dates
 > of brick in Wilson et al. 2009, I am unaware of other ceramics--
 > historic or prehistoric--that have been dated. I e-mailed Dr. Wilson
 > offering to provide some sherds from a prehistoric site in Texas,
 > but received no reply to my e-mail.
 >
 >
 >
 >
 >
 > -----Original Message-----
 > From: Megan Springate <[log in to unmask]>
 > To: HISTARCH <[log in to unmask]>
 > Sent: Thu, Jan 13, 2011 12:10 am
 > Subject: Food for Thought: A New Way to Date Old Ceramics
 >
 >
 > Forwarded from the Public History email list.
 >
 > --Megan Springate.
 >
 > ---------------------------- Original Message
 > ----------------------------
 > Subject: Food for Thought: A New Way to Date Old Ceramics
 > From:    "H-Public editors" <[log in to unmask]>
 > Date:    Wed, January 12, 2011 11:59 pm
 > To:      [log in to unmask]
 >  
--------------------------------------------------------------------------
 >
 > A New Way to Date Old Ceramics
 > Marcia Goodrich
 > Michigan Tech News
 > http://www.mtu.edu/news/stories/2011/january/story35249.html
 >
 > January 10, 2011?
 > If you are an archaeologist, determining when a pot was made is not
 > just a matter of checking the bottom for a time stamp. Dating
 > clay-based materials like ceramics recovered from archeological sites
 > can be time consuming, not to mention complex and expensive.
 >
 > Patrick Bowen, a senior majoring in materials science and  
engineering,
 > is refining a new way of dating ceramic artifacts that could one day
 > shave thousands of dollars off the cost of doing archaeological
 > research.
 >
 > Called rehydroxylation dating, the technique was recently developed  
by
 > researchers at the University of Manchester and the University of
 > Edinburgh. It takes advantage of ceramics? predictable tendency to
 > bond chemically with water over time.
 >
 > ?It?s simple,? says Bowen. First, dry the sample at 105 degrees
 > Celcius. This removes any dampness that the ceramic might have
 > absorbed.
 >
 > Then, weigh the sample and put it in a furnace at 600 degrees  
Celsius.
 > The chemically bonded water, in the form of hydroxyl groups (single
 > atoms of hydrogen and oxygen bound together), forms water vapor and
 > evaporates. ?When you do that, you mimic what the sample was like  
when
 > it was originally fired,? says Bowen.
 >
 > Then weigh the sample again and leave it alone. Over the next several
 > weeks, the ceramic will react with water in the air and gain weight.
 > Plot the gain against a time constant, and the shape of the curve
 > tells you the age of the ceramic. Theoretically.
 >
 > But it ain?t necessarily so, Bowen discovered, working with his
 > advisors, Jaroslaw Drelich, an associate professor of materials
 > science and engineering, and Timothy Scarlett, an associate professor
 > of archaeology and anthropology. ?The dating process turns out to be
 > more complicated than the literature suggests,? he says.
 >
 > Using shards of pottery dating from 1854 to 1888, which Scarlett
 > provided from an archaeological dig in Utah, Bowen tried out the
 > original dating technique at different temperatures and got
 > significantly different ?ages? for the shards. He then developed a  
new
 > equation that addresses those temperature effects, as well as the  
fact
 > that rehydroxylation is actually a two-step process: First, water
 > vapor physically penetrates the pottery. Then, it bonds chemically to
 > the pottery?s constituent minerals.
 >
 > Bowen?s equation worked better, but not well enough to generate
 > definitive dates. Humidity fluctuations affected the samples?  
weights,
 > skewing the results. Now the research team is using new methods to
 > provide constant humidity and will run additional tests over the next
 > few months on various types of ceramics of different ages.
 >
 > They won?t only be using rare, antique pottery this time, however.
 > ?This year we are using broken pieces of brick from the Houghton
 > Parking Deck; it?s easier to come by,? says Bowen. ?Somebody hit it
 > with their car, and when I saw the pieces, I thought, ?Oh! Sample!??
 > If all goes as planned, each of those samples dated by Bowen and
 > fellow researcher Tyler Botbyl, a materials science and engineering
 > junior, will turn out to be about forty years old.
 >
 > The researchers believe their work has huge potential. ?This will  
be a
 > new, low-cost tool allowing archaeologists to derive dates from
 > objects made over 10,000 years of human history,? said Scarlett.
 >
 > Bowen wrote a paper on the team?s initial findings, which is being
 > considered by the Journal of the American Ceramic Society. The paper
 > was co-authored by fellow undergraduate Helen Ranck and both  
advisors.
 > His work was previously supported by a McArthur Research Internship
 > and a Michigan Tech Summer Undergraduate Research Fellowship. It is
 > currently supported by a Michigan Space Grant Consortium  
Undergraduate
 > Fellowship.
 >
 > Michigan Technological University (mtu.edu) is a leading public
 > research university developing new technologies and preparing  
students
 > to create the future for a prosperous and sustainable world. Michigan
 > Tech offers more than 130 undergraduate and graduate degree programs
 > in engineering; forest resources; computing; technology; business;
 > economics; natural, physical and environmental sciences; arts;
 > humanities; and social sciences.
 >
 > --
 > H-Public
 > To post to the list:  [log in to unmask]
 > Home page:  www.h-net.org/~public
 > sponsored by the National Council on Public History (www.ncph.org)
 >
 >
 >