British Museum Turquoise Conference

[Mike R]

Listeros,

Turquoise, Henry Christy and museum collections:
an interdisciplinary conference
Friday 11 – Sunday 13 December
BP Lecture Theatre, British Museum

A conference dedicated to the history and cultural use of turquoise to
mark the bicentenary of the birth of the British collector Henry
Christy. Christy is associated with nine rare Aztec turquoise mosaics
that will be on display in the exhibition Moctezuma: Aztec Ruler. The
sessions will address the meanings and significance of turquoise in
its archaeological, historical and ethnographic dimensions by bringing
together the expertise of museum curators and scientists from a
variety of disciplines from Mexico, North America and Europe.
£20, students and senior citizens free

DAY 1

Jill Cook
(Senior Curator of Archaeology of Human Origins, British Museum)

In Pursuit of the Unity of the Human Race:
the Life, Work and Collecting of Henry Christy (1810-1865)
A year before his death aged just 55 and in the only academic
publication which he authored on his own, Henry Christy concluded that
his archaeological researches in France with renowned palaeontologist
Edouard Lartet, confirmed ‘the cherished idea of the unity of the
human race’. Read to the Ethnographical Society of London in June
1864, this conclusion vindicated the contemporary ethos of its
members, as well as the convictions which had driven Christy’s life
long pursuits. This investigation of Christy’s life links his
humanitarian work, travel and collecting with his Quaker beliefs,
liberal views and entrepreneurial background. It suggests that, in
1859, the publication of Darwin’s On the Origins of the Species and
the debate about human antiquity gave new purpose to Christy’s early
pursuits and unveils his influence on the emergent disciplines of
ethnography, archaeology and anthropology.

Marjorie Caygill
(Centre for Anthropology, British Museum)

Christy, Franks and the British Museum’s Turquoise Mosaics
Our current knowledge of the provenance of the British Museum’s nine
turquoise mosaics will be summarized and the parts played by Henry
Christy (1810-65), collector and businessman, and A W Franks
(1826-97), collector and curator, in the acquisition of these objects
will be outlined. Although the origins of the mosaics are largely
untraced prior to the nineteenth century, some further details of
their more recent history prior to their acquisition by the Museum
have emerged.

Michael Thompson
(Independent scholar, Cambridge)

The Influence of Evolutionary Ideas on Victorian Collections
There are many motives for collecting in all periods or it could give
satisfaction in many forms. In Victorian times from the 1840’s a sense
of evolutionary progress , the two are not always separated, caused
collectors to wish to demonstrate this by showing development in
ethnological and prehistoric material. The Great Exhibition of 1851
which glorified the level of contemporary manufacture and machinery
stimulated thought on how this was achieved from simple beginnings.
The classic case is Lane Fox, later Pitt-Rivers, whose first
collection still survives at Oxford. The development of his thought is
discussed and contrasted with the more strictly scientific origins of
John Lubbock’s thought derived from Darwin himself. Finally an attempt
will be made to fit Henry Christy into this background.

Christian Feest
(Museum für Volkerkunde, Wien)

Two Mexican Turquoise Mosaics in Vienna
The collections of the Museum of Ethnology Vienna include two works
representing the tradition of Mexican turquoise mosaic art, whose
documentary history in Austria may be traced back to 1596. One is a
turquoise mosaic shield matching the description of such items in
early shipment lists from Mexico and closely resembling a shield drawn
around 1520 by Hans Burgkmair; the other is a frame for a semi-
globular mirror in the pre-Spanish tradition, covered with a mosaic of
shell, jade, turquoise and glass, and featuring a tongue attached by
means of a piece of iron wire, thus illustrating the persistence of
mosaic work into the colonial period. The paper offers a technical
description of the two items, an account of their collection history,
and a comparative analysis of their iconography.

Laura Laurencich-Minelli
(Dipartimento di Paleografia e Medievistica, Università di Bologna)

A Glance at Bologna's 16th-17th Century Museums and their Aztec Items
The Mexican items of the time of the conquest (mostly Aztec ones), and
the meaning they had in Bologna's Antonio Giganti (1535-1598), Ulisse
Aldrovandi (1522-1605) and Ferdinando Cospi (1609-1686) museums are
presented in this paper highlighting that the Museo Giganti was
integrated, probably as a gift, into the Aldrovandi collection around
1597. The fact that the three collectors, in spite of their interest
for the new discovered lands and culture, were opened mostly to the
Aztec ones and not to Peru and to the Incas items is also discussed.
According to the three museums inventories, some traces of the
exhibition and of the organization of these museums including the
position of the Aztec items can be reconstructed. At the time, the
naturalia were mixed with the artificialia but with some exceptions
that seems connected to storing problems and to the activity of their
owners: a clergy man the former, a scholar of Bologna's University the
second-one, and a senator the third-one. The list of donors that we
could reconstruct by the inventories are also examined and discussed,
as well as the relationship between Bologna's museums and the
contemporary Medici Guardaroba (wardrobe). It appears that the
Giganti, the Aldrovandi, and the Cospi museums, and their Aztec items,
were a place of research opened to the public as well as being a place
where to receive gifts such as the exceptional Aztec atlatl which
Valerio Zani gifted to the Aldrovandi Museum in 1665 (or 1677). This
happened through the time when they were transferred to the Palazzo
Pubblico (1603, 1657) until and after the death of their collectors.
Later on (ca. 1742, 1743), when the Aldrovandi and Cospi museums were
transferred to the "Stanza delle Antichità" of the Istituto delle
Scienze, they lost their identity and the unity of the naturalia and
artificialia, but they continued to receive gifts. The last one among
the Aztec items, was the musical instrument carved out of a human
femur gifted to Pope Benedetto XIV in 1745. In this presentation a
special attention is given to the significance attributed by the
collectors to some outstanding turquoise mosaic items such as the mask
from the Aldrovandi museums, and to the two sacrificial handles of the
Cospi's collection.

Maria Antonietta Fugazzola and Elisabetta Mangani
(Museo Pigorini, Roma)

The Kircherian Museum and the Aztec Mosaics in Rome’s Museo Nazionale
Preistorico Etnografico
Father Athanasius Kircher created the “Museo Kircheriano”, between
1634 and 1680, in the premises of the Jesuit palace in Rome named
“Collegio Romano”. Athanasius Kircher put together an extraordinary
scientific museum collecting fossils, minerals, roman sculptures and
inscriptions, paintings of the most famous painters of the XVI
century, portraits of popes and cardinals, maps, clocks, and
astronomical instruments. The main attraction of the museum were
automata, made according to the picturesque Baroque taset; but there
were also collected ethnographic objects with the specific purpose of
educating the seminarians who were destined to reach the Jesuit
missions around the world. The Gallery of Athanasius Kircher became a
meeting point for all scholars, both Italian and foreign, who came to
Rome. Next to the Kircher Museum, the National Prehistoric
Ethnographic Museum was opened in 1876: this new museum included the
ethnographic objects of the Kircher Museum, and collected and
exhibited more several masterpieces of Aztec art, such as mosaic-
decorated objects.

Antonio Aimi
(Dipartimento di Scienze del Linguaggio, Università di Milano)

Exotica from the Settala Museum and Other Northern Italian Collections
In the 16th–17th century Milan and other northern Italian cities
witnessed to the emergence of important collections of exotica. These
were part of eclectic collections that followed taste and trends
fashionable in Europe at the time. The research carried out by the
author and other scholars on the Museo Settala in Milan and additional
northern Italian cities’ collections, revealed an extremely
fascinating and surprising inventory of objects. This is particularly
interesting given that Italy was virtually cut off the transatlantic
trade routes that connected Africa, Asia and the New World. It is not
clear, however, if what seems to be a peculiar interest for exotica is
due to the Renaissance courts’ cultural life, or it is rather only
apparent, and it is simply the result of the fact that Italian memory
of the passion for exotica and antiquities is better preserved in this
country than in other places. In any case, it is apparent that
understanding the exotica phenomenon requires not only a study of the
antiquities, but also the ways in which non-European cultures were
represented in literature, art, and science during that period. In the
case of the Settala Museum in Milan, the existence of five large
illuminated manuscripts, not only shows a largely disappeared
collection, but represents the collector’s working tool. This enables
an understanding of the exotica as objects part of a surprisingly
‘modern’ pre-ethnographic classification system and research that
exceed the baroque taste of the time. It is thus evident that
Schlosser’s judgement of this collection, alongside more recent
evaluations that tend to juxtapose Italian collections of the 16th
against those of the 17th century are essentially wrong. What is more,
the codices’ conservation (there were originally seven that were sold,
and further accidentally retrieved), and the fact the correct
interpretation of the Settala Museum almost exclusively depends on
them, shows that our understanding of the cultural context of 16th–
17th century collecting is often haphazard.

DAY 2

Frances Berdan
(Department of Anthropology, California State University San
Bernardino)

Turquoise in the Aztec Imperial World
Central Mexico in the century prior to the Spanish conquest was
dominated by an alliance of three powerful Basin of Mexico city-
states: Tenochtitlan, Texcoco and Tlacopan. Together, they forged what
has come to be known as the Aztec empire. The primary partner in this
imperial alliance was Tenochtitlan, home of the Mexica.
The Mexica and their neighbors repeatedly demonstrated their power
over human and material resources by extravagant displays on their
persons, in their palaces, in sumptuous feasting, in the adoration of
their gods and in flamboyant religious ceremonies. These displays
required large quantities of exotic materials, the most notable of
which were tropical feathers, gold, jadeite, and the subject of this
paper, turquoise. These materials were fashioned into exquisite and
symbolically laden objects destined for use by rulers, priests and
other elites.
Objects fashioned of turquoise were mosaics or beads, and included
diadems, lip plugs, nose plugs, ear plugs, necklaces, pectorals,
armbands, masks, helmets, shields and disks, mirrors, sacrificial
knives, and possibly capes with turquoise pieces attached. Worn or
wielded by elites, priests, deities or deity impersonators, such
objects were significant markers of exalted social position and
extraordinary political power. Yet despite its importance and intense
use, turquoise was not natively available to the Mexica in the Basin
of Mexico and needed to be obtained through imposed tribute, market
exchange, and foreign trade.
Drawing on sixteenth-century pictorial codices and textual historical
sources (as well as extant objects), this paper addresses the manner
in which the Aztec elite acquired and used both raw turquoise and
turquoise objects. It includes questions of how turquoise served the
needs of the state and different members of the aristocracy, the
context of manufacturing turquoise objects, and the extent to which
the state controlled access to raw materials and skilled artisanship.

Karl Taube
(Department of Anthropology U.C. Riverside)

The Symbolism of Turquoise in Postclassic Mexico
Along with metallurgy, turquoise does not become widespread in
Mesoamerican until roughly a.d. 900, at the beginning of the
Postclassic period. Deriving from the American Southwest, turquoise
began to supplant jadeite as the most important gemstone in ancient
Mesoamerica. Thus it is likely that the Aztec term for jade,
chalchihuitl, derives from the words for sand, xalli, and turquoise,
or xihuitl. However, the symbolic significance of turquoise was quite
distinct from that of jade, a stone widely identified with water and
maize in ancient Mesoamerica. In contrast, turquoise was very much a
“sky stone” and related closely to the sun, fire, and meteors. Along
with the Aztec god of fire, Xiuhtecuhtli, meaning Turquoise Lord,
there was also the Xiuhcoatl, the turquoise fire serpent. The oddly
segmented body of this creature probably relates to a widespread
Mesoamerican belief that meteors convert into worms and caterpillars
upon striking the earth. The Xiuhcoatl spearthrower wielded by
Huitzilopochtli and other Aztec gods is a star-shooter of meteoric
darts. Along with examining the Aztec symbolism of turquoise, this
study also discusses turquoise iconography pertaining to the earlier
Toltec, including reliefs from Tula and Chichen Itza. It appears that
many aspects of the “cult of turquoise,” including particular costume
regalia, originated with the Early Postclassic Toltec.

Patrick Johansson
(Institute of Historical Research, University of Mexico)

Teoxihuitl. Turquoise in Aztec Thought and Poetry
Precious stone which magnified garments, statues, masks and jewels in
pre-Columbian times, turquoise was also a conceptual gem of Aztec
thought. The nahuatl word for it: xihuitl, according to the Indigenous
informants of Spanish friar fray Bernardino de Sahagún, comes from
xihuitl "the herb which is sprouting".
It is also symbolically related to a color between blue and green, to
fire, to Huizilopochtli as Xiuhpilli, the sun-god, to different birds,
to the year and more generally to Time. In a literary context, it
glitters in a myriad of metaphors and poetic expressions. In pictorial
books, its function ranges from a simple phonetic sign to a complex
visual significance. Starting from the meaningful etymological ground
in which the nahuatl word for turquoise is rooted, we will analyze a
variety of verbal and pictorial texts in which turquoise is
involved.

Peter Whiteley
(Curator of North American Ethnology, Division of Anthropology,
American Museum of Natural History)

Tsorposiniqw patangsi (Turquoise and Squash Blossom): Puebloan
Oppositions of the Longue Durée
The symbolism of turquoise in contemporary Pueblo cultures of New
Mexico and Arizona transects linguistic and geographic boundaries.
Color values grounded in hard substances—turquoise, jet, olivella, and
spondylus shells—articulate cosmologies both temporally and
spatially: from the vertical world layers through which humans
originally emerged, to the directional mountain shrines anchoring the
ritual landscape. The turquoise-squash opposition configures a key
principle of social organization among the Rio Grande Pueblos: from
the eponymous dual kiva system of the Keresans to the parallel Winter-
Summer moieties of their northern neighbors, the Tewa. Even among the
western-Pueblo Hopi of Arizona, where social organization is less
obviously dualistic, the turquoise-winter/squash blossom-summer
dialectic reverberates through ritual practices and aesthetic
correspondences: from Katsina costumes to sand altars, songs, and
sacramental offerings. Hopi tsorposi (turquoise), literally ‘bluebird
seed,’ remains (in flake form) a valued ritual offering, and, as
shaped and unshaped stones, the most common element of personal
adornment. Squash blossoms (patangsi)—as painted designs on tablitas,
or sculpted elements on masks or headdresses—similarly pervade Hopi
ritual expression. Via worked spondylus shell, and now often imported
Italian coral, squash as color is worn by many, especially in
aesthetic counterpoint to turquoise, and, in finished necklaces, is a
favorite trade item from Santo Domingo pueblo. Within the multi-clan
Hopi social system, there are Tsor- (mountain bluebird, but with a
turquoise implication) and Paatang- (squash) clans. Such symbolic
patterns thus unify the Pueblos across major language boundaries and
social-structural differences, extending also to non-Puebloan Native
cultures in the Southwest, especially the Navajo. Architectural
ornamentation in the great kivas of Chaco Canyon, and evidence of
ritual costume throughout the Ancestral Puebloan Southwest, suggest
these color/hard substance oppositions are deeply entrenched. Their
presence in Mesoamerica too suggests a macro-regional symbolic
structure of the longue durée, dependent in part on a widespread
system of trade in ritual commodities (including turquoise from New
Mexico and spondylus shell from Baja California). Through comparative
cultural contexts within the Puebloan Southwest and beyond, this paper
inquires into the meanings of turquoise and squash as elemental
symbols organizing social life, the cosmos, and ritual practice.

Henrietta Lidchi
(Keeper, Department of World Cultures, National Museums Scotland)

On the Eternal and the Elusive: on the Use of Turquoise in the
American Southwest
This paper will address questions of importance of turquoise through
the aspect of local mimicry, and the value of skeuomorphs. In a
hierarchy of valued materials, turquoise is significant throughout the
Southwest, having ceremonial, aesthetic and economic value. However
turquoise harmoniously combined with silver is also the signifier of
Southwestern jewellery to the connoisseur and the consumer.
Consequently turquoise has become the object of mystique, fascination
and connoisseurship in its own right, but also the subject of
mimicry. It can be argued that the huge demand for Southwestern
jewellery from the outside cannot be adequately met with a ready
supply of high value American-mined turquoise, consequently, a ready
supply of alternatives to the natural stone, a stone which is
essentially soft and may be unpredictable to cut, is necessary. This
paper will explore questions of identification and recognition as well
as historical aspects of imitation, to analyse the connections and
disjunctions between jewellery as a commercial and a collectible art,
and a form of ornament with distinct indigenous meanings.

Gail Bir and Yazzie Johnson
Gail Bird (Santo Domingo/Laguna) and Yazzie Johnson (Navajo)
(designers/artists)

Shared Images: Continuity and Innovation in the Use of Turquoise
The ceremonial and ornamental purposes of the turquoise have a long
history in the Southwest, a history that is continuously invigorated
by the work of contemporary jewellers. We will review the tradition
of lapidary work in the Southwest, looking at pre-contact Hohokam
mosaic work and early examples of bead making. Briefly considering
the origins of Navajo metalworking, we will consider the rise of the
use of silver and how this has created the context for the setting and
presentation of stone. We will then turn to the growth and
development of individual styles within the Southwest in the range of
stone setting, bead making and lapidary work. We will feature and
cite the work of individual makers, looking especially at contemporary
jewellery. This will show the circulation of influences and styles
and address the continued importance of turquoise to Southwest Native
communities.

Shane Herndren
(American Indian Arts and Crafts Association)

We Wear Our Wealth: Turquoise Cultural & Historical Context
Anthropologist have described Navajo people as semi-nomadic. Our life
way has been one of mirroring the world around us. Moving from one
location to another as the seasons change to maximize the life
sustaining products of the earth, we maintain balance and harmony with
in the universe.
This life way is best reflected in the personal adornment of the
people. Turquoise represents protection, the cardinal direction south
and ones “wealth”. Wearing this sacred stone serves as a reminder of
our place in the universe as well as a symbol to others of our
“success”. In these modern times it has also become a means by which
to sustain life.
Artist incorporates Turquoise in their work and their lives so as to
maintain their traditions while also providing for their families.
Turquoise reflects our lives.

Cheri Falkenstien-Doyle
(Curator, Wheelwright Museum of the American Indian)

Turquoise and Silver in the American Southwest
Historians tell us that Navajo and Zuni silversmiths first set
turquoise into silver jewelry in about 1880, but that the stone did
not come into common use until the beginning of the twentieth century,
when American-owned turquoise mines operated throughout the
southwestern United States. Few sources offer detail about the
interactions that occurred among mining companies, retailers,
reservation traders, and Native jewelers that made turquoise available
and led to its iconic pairing with Indian-made silver. Through the use
of archival resources in Arizona, California, New Mexico, and Nevada,
this paper illuminates the relationships that brought turquoise into
prominence in the American Southwest.

DAY 3

Douglas Magnus
(Cerrillos Mines)

Southwest Turquoise: A View From Cerrillos Mines
Turquoise is a mineral and gemstone with a vast and somewhat
mysterious lore. Its varieties of hardness, color, and matrix
characteristics are seemingly endless. Its geology is little
understood. Turquoise intrigues and surprises. Though its beauty is
universally recognized, its popularity, fashion, and spiritually?
connected usage vary from era to era, and place to place. There is
nothing else in the natural world quite like turquoise. My 35 years
working with Cerrillos Turquoise, from the mines to the finished
product, has given me the extraordinary opportunity to become familiar
with the subtle variations, and the chance to compare stones from the
same formation against other turquoise materials from locations around
the world.

Since learned works on the subject abound I do not intend here to
review the typing of turquoise: natural, altered and artificial.
Rather, I will present a short overview of my operation, which
includes my hands?on experience with these materials, after which I
will be happy to discuss items of specific interest, and to answer
questions.

My experience draws upon my ownership of 16 mines on Turquoise Hill,
in the Cerrillos District of Santa Fe County, New Mexico. Owning these
historic mines has allowed me, over the past 21 years, to meet and
learn from many geologists, mineralogists and archaeologists. Although
I am not academically schooled, by my ownership of the mines, by my
lifelong work with the mineral for use as adornment, and by my
constant exposure to the examinations of the regional archeological
and historical connections to my mines, I believe I have a well
grounded and possibly unique perspective on the role of Turquoise in
the American Southwest. The 19th and 20th Century connection with
Tiffany & Company provides a particularly interesting chapter to the
modern history of Turquoise usage and evaluation.

As well, my interest in the archeological Southwest and Mexico has
taken me, repeatedly, to many ancient and exotic sites, from Colorado
to Chichen Itza, with many artisan workshops and museums in between. I
continue to be intrigued by the question of who the people were who
first mined Turquoise in the Cerrillos, Little Hills, and how they
might have organized and operated their mining, processing and
trading. Based solely on its scale, turquoise dealing must have been a
serious business.

My fascination with turquoise includes the sense of honor and
obligation that comes from my temporary custody of these Cerrillos
mines. For me it is an honor and a privilege to carry for the
tradition of the ancient and sacred stone as respectfully as possible,
both in caretaking the property and in my design and use of it. When I
am at the mines or when I am crafting a stone, I feel myself in the
presence of the Ancient Ones. In my power point presentation, I will
be focusing on my own experiences with Turquoise in general, my
personal knowledge and experiences with Native American jewelers, and
an overview of how the Turquoise scene has evolved in my lifetime.

Caroline Cartwright
(Department of Conservation, Documentation and Science, British
Museum)

Mastering Materials: Comparative Properties of Turquoise Mosaic Raw
Materials and their Significance for Mosaic Technology
The nine Mexican turquoise mosaics in the British Museum have
undergone intensive investigation to study the many natural materials
selected for their manufacture. This paper describes the most recent
detailed scientific examination of these materials using optical and
scanning electron microscopy. It evaluates to what extent both the
microstructural and decorative properties of different raw materials
were understood by Aztec and Mixtec specialist craftsmen and which
factors governed their selection.

Rebecca Stacey
(Department of Conservation, Documentation and Science, British
Museum)

An Integrated Approach to Understanding the Selection and Fate of
Turquoise on Mexican Mosaics in the British Museum
The British Museum’s Mesoamerican collections include nine Mexican
mosaics, all of which display extensive use of turquoise. This paper
will examine distribution of this material in the construction of
these objects drawing on fresh results from recent examination and
analysis. The challenges for ongoing study of the origin and fate of
the turquoise in these mosaics will be discussed.

Alyson Thibodeau
(Alyson Thibodeau1, John T. Chesley1, Joaquin Ruiz1, David J. Killick2
1Department of Geosciences, The University of Arizona, Tucson,
Arizona, USA.
2 Department of Anthropology, The University of Arizona, Tucson,
Arizona, USA)

Tracing Turquoise from Site to Source across the Greater American
Southwest and Mesoamerica
The mining, manufacture, and long distance trade of turquoise by
prehistoric cultures across Southwestern U.S. and Mexico has been an
enduring theme in the archaeological literature of these areas.
Turquoise is widely thought to have been an important component of the
cultural and material exchange between societies in the prehistoric
Greater Southwest and Mesoamerica.

Contact and trade between these two regions is archaeologically well-
documented. By the Sedentary phase of the Hohokam (ca. 975-1150 CE)
cultural practices of Mesoamerican origin were adopted in southern
Arizona, the most obvious traces of which are ballcourts and platform
mounds. This period, contemporary with the Great Houses of Chaco
Canyon, was also marked by the acquisition of Mesoamerican luxury
goods, including cast copper bells and pyrite mirrors. In turn, it
has long been suggested that Southwestern societies traded large
quantities of turquoise to Mesoamerica beginning at this time. Many
in the archaeological community believe the turquoise mines of
Cerrillos Hills (southwest of Santa Fe, New Mexico) likely supplied
much of the turquoise for trade with Mesoamerica, and that these mines
were the source of the huge quantities of turquoise recovered from
Chaco Canyon.

Despite decades of study and debate, there has been no scientific
consensus regarding how to identify the geologic source of turquoise
recovered from archaeological sites across the Greater American
Southwest and Mexico. Thus, it has remained difficult to test the
hypotheses put forward by archaeologists regarding the role of
turquoise in the interactions between different cultural groups in the
Southwest and their long-distance relationships with Mesoamerican
societies.

Radiogenic isotope geochemistry provides a promising solution to this
long-standing problem. By measuring the isotopic composition of trace
amounts of lead and strontium in turquoise, we show that individual
turquoise sources across of the American Southwest have constrained
and often unique chemical signatures associated with them.

We are now using these chemical signatures to identify the source of
turquoise from a variety of archaeological sites across the American
Southwest including: early Basketmaker-III sites in the Rio Grande
Valley of New Mexico, colonial period Hohokam sites in southern
Arizona, and from Pueblo Bonito, the largest Great House in Chaco
Canyon, New Mexico. These lead and strontium isotopic measurements
provide the archaeological community with a framework that has the
potential to transform our knowledge regarding when and where
prehistoric Southwestern cultures mined turquoise, and to help us to
better understand the long distance networks between these cultures
and Mesoamerica.

Mostafa Fayek
(Department of Geological Sciences, University of Manitoba, Winnipeg,
MB Canada)

Cracking the Code of Anasazi Turquoise
The procurement and trade of turquoise was as important to pre-
Hispanic societies of Mesoamerica (e.g., Mayans and Aztecs) and the
southwestern United States (Anasazi) as silver was to the colonial
societies of northern New Spain. A remarkable number (>1,000,000
pieces) of turquoise artefacts have been recovered from Anasazi,
Mayan, and Aztec archaeological sites. Yet the sources of the
turquoise and spatial and temporal patterns of the turquoise trade
networks remain elusive. For decades archaeologists have sought to
chemically “fingerprint” turquoise, thus allowing them to link
specific artefacts to their sources and reconstruct turquoise trade
networks. However, these studies have met with limited success due to
the intrinsic limitations of trace element or chemical analysis of
complex minerals such as turquoise, which can range in color and thus
vary chemically within a single sample or mine. To overcome these
limitations we developed an isotope method that utilizes the stable
isotope of hydrogen (2H/1H) and copper (65Cu/63Cu) to “fingerprint”
turquoise, thus allowing us to link turquoise artefacts to prehistoric
mines hundreds of kilometers from Anasazi cultural sites. This method
is successful because the geography and geology of turquoise deposits
dictate the isotopic signature of turquoise.

Our method is a relatively non-destructive because it utilizes the in
situ micro-analytical capabilities of the Secondary Ion Mass
Spectrometer (SIMS). SIMS is capable of performing accurate (i.e., ‰
to sub-‰), in situ isotopic measurements on solid samples as small as
50 micrometers. The small sample size required for analysis is
particularly advantageous for analyzing precious archaeological
artifacts and allows us to avoid inclusions and altered spots in
turquoise samples, which could cause scatter in the data if bulk
analytical techniques are employed on powdered samples.

We measured the isotope ratios of hydrogen and copper in turquoise
samples from over twenty mines located in six prehistoric mining
districts throughout the southwestern United States and over twenty
artifacts recovered from Chaco Canyon, Aztec and Salmon Ruin.
Approximately 200 analyses were obtained. Our results suggest that
turquoise did not necessarily flow from north to south as expected,
but rather was sent to a centralized location such as Chaco Canyon.
In addition, our data suggest that the turquoise trade and thus the
Chaco network influence extended several hundreds of miles northwest,
and therefore had a much larger sphere of influence than expected.
Reconstructing these turquoise trade networks will provide important
insights into the cultural intensification of the social systems along
the northern frontier of Mesoamerica (northern Mexico) and in
southwestern portions of the United States. The initial success of
this technique promises to provide a method for archaeologists to
source turquoise found at sites across the continent, providing new
insight into pre-contact trade patterns in North America.

Patricia Meehan and Valerie Magar
(Conservation Specialist, Coordinación Nacional de Conservación del
Patrimonio Cultural (National Coordination of Conservation of Cultural
Heritage); Instituto Nacional de Antropología e Historia (National
Institute of Anthropology and History)
Researching Pre-Columbian Mosaic Techniques and Symbology. A Case from
Tula, Mexico
In 1992, an extremely decayed offering, essentially composed by a
turquoise mosaic was excavated from one of the main buildings at the
archaeological site of Tula, in the current state of Hidalgo, in
central Mexico. This article will focus on the project undertaken in
1993 and 1994 for its research and conservation. The initial
activities of this project focused on a historical and iconographical
research on turquoise mosaics, and their specific relevance for the
ancient pre-Columbian city of Tula, the birthplace of turquoise mosaic
according to ancient Mexican myths. At the same time, micro-
excavations were slowly undertaken on the materials retrieved during
the excavation process, and the different materials were analysed. The
difficult decision-making process for the conservation and restoration
treatments considered the nature and preservation of the original
materials, the potential unity of the mosaic, and the relevance of the
archaeological and ethnological data. In spite of the poor
preservation conditions, and the damages induced during the excavation
process, the thorough interdisciplinary research allowed for a fairly
accurate understanding of the offering and its evolution during its
burial and retrieval. A somewhat unusual decision was made to opt for
a hypothetical reconstruction of the turquoise mosaic, based on the
will to better understand the original manufacture techniques and the
design of these mosaics.
Laura Filloy Nadal
(Senior Conservator, Museo Nacional de Antropología Mexico City,
Mexico)

“Mineralogy and Manufacturing Technique in a Group of Archaeological
Greenstone Mosaics from Three Classic Period Mesoamerican Sites”
Recent excavations at Teotihuacan and in the Maya area have led to the
discovery of a number of greenstone on wood mosaics. The most recent
excavations in the heart of the Moon Pyramid uncovered a unique human
sculpture made of serpentinite, obsidian, and limestone tesserae. At
the same time, a number of Mexican archaeological projects in the Maya
area have brought to light a magnificent corpus of thirteen mosaic
masks from Oxkintok, Dzibanché, Calakmul, and Palenque that were
crafted from different green minerals, such as jadeite, albite,
kosmochlor, and chrysoprase.

In the last decade, restorers at INAH worked on restoring these
objects by applying a new methodology to ensure their proper
assemblage. The restoration and the detailed study of the sculpture
allowed us, on the one hand, to identify a wide range of prestige
materials used, and on the other, to conjecture the technical sequence
necessary to produce the mosaic.

At the same time, mineralogical and technological studies have been
conducted to determine the materials used, the origin of the raw
material, and the manufacturing technique used in each case. Although
all of the workshops where these handsome objects were carved have not
yet been discovered, it has been possible to identify manufacturing
patterns that make it possible to locate the cultural area where they
were made. Also, different analyses (optic microscopy, x-ray
diffraction, PIXE, Ramman spectroscopy, x-ray fluorescence, MEB and
micro-chemical tests) permitted the identification of minerals and
wood species used for the mosaics.

This work details the process of restoration and the analyses
conducted on three magnificent examples: the funerary mask of K’inich
Janaab Pakal of Palenque, a mask from Oxkintok, and the human figure
recovered in Burial 6 of the Moon Pyramid at Teotihuacan.

Programme may be subject to change.
http://www.britishmuseum.org/whats_on/events_calendar/december/turquoise_
conference.aspx

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