Smith (1958) states that his article “Technological Research on Ancient Glass” could have instead been called “Ancient Glass Enters the Atomic Age” because “our increased knowledge of atomic structure and behavior is about to make ancient glass more meaningful” (111).  He expects that, with advancements in chemical analysis, glass will be easier to date.  One of the techniques that he discusses is EMPA.  Smith contends that the electron microprobe is a “useful new refinement of X-ray fluorescence” (113).  As a spot analytical technique, EMPA can be used “to determine the degree or absence of homogeneity of a specimen by observing the changes in composition when the tiny beam is moved along the surface” (113).  Smith hopes that EMPA and other new analytical tools will allow archaeologists to establish area-period compositional norms for ancient glasses and to identify the sources of raw materials based on characteristic fingerprints.

    Hall (1963) discusses six analytical techniques that can be applied to archaeological material to determine chemical composition, and among them is electron microprobe analysis.  He describes the apparatus and some possible applications: “For instance, if we have a small flake from a picture which consists of a number of layers of paint, each layer can be chemically identified although each one may only be a few microns thick” (188).  The microprobe is also well suited to the investigation of surface enrichment of metal artifacts.  Also it is, at times, desirable to identify the small inclusions within metals, ceramics, stoneware, and so forth and “the only method we have at present” (189) is electron microprobe analysis.  Hall states that the microprobe “is a new tool and there is little doubt that, although it is an expensive piece of equipment (above £15,000 [$150,000 in adjusted dollars]), it will find extensive use in the arts world during the next few years” (189).

    In 1965, Bennyhoff and Heizer published an article on their utilization of NAA to determine the manganese in sherds from Cuicuilco and Teotihuacan in the Valley of Mexico.  They concluded that there was trade between these sites because three sherds from Cuicuilo had manganese contents similar to ceramics produced at Teotihucan.  Ceramic analyst Anna Shepard (1966) questioned their methods in a later article.  She states that their study “raises fundamental questions about choice of analytical methods and interpretations about choice of analytical methods and interpretation” (870).  Foremost of her protests is the choice of Bennyhoff and Heizer to use neutron activation analysis (NAA).  Shepard asserts that NAA “does not identify the potters’ raw materials” (871).  NAA can measure the bulk composition of a sherd with a high sensitivity, but the technique cannot determine the distributions of the elements it detects.  She points out that, for tempered pottery, compositional analysis “raises problems of interpretation: did the significant elements come from the clay, or from the temper, or from both?” (871).  Her solution was to use EMPA to find manganese distributions in the sherds from Cuicuilco and Teotihuacan.  Analyses with the electron microprobe revealed that the manganese occurred principally in the clay, not the temper, in the form of inclusions only one or two microns in diameter.   The manganese content in some of the inclusions approached 15 percent. She contends that, in this instance, use of EMPA“to determine the location of the manganese was a perfect selection of a highly specialized instrument for an exceptional need” (871).  

    J.A. Charles (1968) examined the silver capping on the copper rivets used to attach a handle to a bronze Minoan dagger.  He utilized an electron microprobe at the interface between the copper and silver to examine how the two metals were bonded together.  The microprobe revealed a layer in which both copper and silver were present.  The copper and silver occurred as an eutectic, a mixture of materials that, when they crystallize, one component solidifies and then the other, leaving them as discrete materials rather than an alloy.  It was also demonstrated that possible solders, such as tin or lead, were not present.  Consequently, using electron microprobe analysis, Charles was able to learn something of the metallurgical skills of Minoan craftsmen about 3500 years ago.

    In 1969, R. Giovanoil published an article about his studies of Roman mural paintings with electron microprobe analysis.  He explains that there is “a continuous argument on whether or not Roman mural paintings were to be considered fresco in the strict sense of the word” (53).  Studies have shown Roman frescos differ from modern ones: coarse grains under the pigment layer led to a chemical reaction that results in a more durable painting.  Giovanoil states that EMPA was used to establish the distributions of the major elements with the depth in samples from two different areas.  He explains that these samples “turned out to be, altogether, very different.  Some implied the initial presence of an additional binding material, others were clearly fresco work” (58).

Earlier in the book, Tite discusses how the bonding at the interface between two different metals and other microstructures can reveal information the fabrication techniques used.  Later, he discusses the surface enrichment in gold, silver, and copper coins and other metal artifacts.

    In his article “Physical Science and Archaeology,” Charles (1972) discusses several of the ways in which physics and chemistry have contributed to archaeological studies.  He considers how the study “of artifacts, both as regards composition and structure, can lead to important deductions being made as regards such aspects as origin of material, trade routes for raw material, and methods of manufacture” (136).  He states that heterogeneities in ores and clays have complicated provenance studies, but EMPA “can often produce important information as to the materials employed and the ways in which the metal was produced and fabricated” (138).  He gives two examples, one of which is a study of southeast European copper axes.  It was found that such axes were cast in open molds with a haft-hole cored and were forged into their final shapes.  His second example is his discovery that ancient Minoans bonded silver to copper, which is reported in his earlier article.  

    In 1979, Kamilli and Lamberg-Karlovsky published the results of their electron microprobe analyses of ceramics from Tepe Yahya, Iran.  They analyzed seventeen samples of different ceramic ware styles from Tepe Yahya to ascertain if these styles reflect material and technological variations.  In particular, they were interested in continuity, or a lack thereof, in ceramic production at the site as well as the existence of any outside influences.  Archaeological evidence suggested that, during the fifth millennium, the indigenous population of Tepe Yahya had limited contact with other regions of the Iranian Plateau.  The analyses of the pastes and paints on the ceramic specimens suggested that most of the red, buff, and coarse chaff-rich sherds were produced at the site.  The less-abundant fine gray wares, based on the minerals and firing technique, seem to have been imported but fabricated at a single location.  The preliminary results offer insight into technological developments in the Tepe Yahya region as well as their cultural contacts between 5000 and 3000 BCE.

    In 1982, Freestone published his article entitled “Applications and Potential of Electron Probe Micro-analysis in Technological and Provenance Investigations of Ancient Ceramics.”  He reports that EMPA “has become an established technique, indeed virtually a requirement of much research in the fields of mineralogy and petrology” (99).  Therefore, he claims that it would be unusual “if a technique which had proved so useful in the study of natural silicates was not of similar value in the investigation of” human use of these geological materials (99).  Still, the potential of EMPA “in the field of ancient ceramics is only beginning to be recognised” (99).  As a result, Freestone covers its application to examination of clays, slips, and glazes as well as the determination of provenance and firing temperature.  He also states that the analysis of included minerals might solve characterization problems which, due to the internal variability of the material, cannot be answered with bulk analysis techniques, such as neutron activation analysis.  He states that “often the problems of interest to the mineralogist and petrologist require types of data and sampling and analytical procedures different from those required for the problems of interest” of archaeologists (114).  Accordingly, Freestone asserts that “the impetus for the assemblage and analysis of the required petrological-mineralogical data base must come from the archaeological community” (114).

    In 1984, Merrick and Brown investigated the potential of the electron microprobe to analyze obsidian artifacts to determine provenance, and they demonstrate their technique with artifacts from four archaeological sites in Kenya.  They explain that it “is often of interest to determine the source of obsidian used for the production of stone artifacts,” and they report that many “techniques have been applied toward this goal, including macroscopic and microscopic petrographic determinations, analysis of magnetic properties, and various chemical studies” (230).  Merrick and Brown hold that each method has strengths and weaknesses, but they propose that EMPA is particularly useful.  The authors state that EMPA is rapid and that it “yields considerable amounts of data on small amounts of sample” (230).  Merrick and Brown claim that, despite its drawbacks, “the microprobe can be a very useful tool in obsidian characterization studies” (230), and they contend that this “preliminary study has demonstrated the utility of the electron microprobe in rapidly and relatively inexpensively establishing the probable source of obsidian artifacts” (235).

    Abbott and Schaller (1985) used electron microprobe analysis of Hohokam pottery in order to ascertain if there was exchange in the Salt River Valley, Arizona.  They correlated several ceramic varieties, based on temper, with ten zones of distinct rock types in this valley.  Hypotheses about the use of these rock types for pottery production at various sites were checked by Abbott and Schaller using microprobe analyses of the pottery’s clay component.  It was found that associations between clay and temper varieties could be utilized to discern between locally produced pottery and imported wares.  Their findings from the Pueblo Grande site indicate that there existed a complex system of temper procurement and exchange of large numbers of two ceramic wares both within and between the prehistoric canal systems found throughout the Salt River Valley.

    Henderson (1988) reports on new compositional classifications of mixed-alkali glasses.  He claims the compositional categories established in the 1960s have “withstood the test of time” (77), particularly for glasses of first- and second-millennium BCE.  Using electron microprobe analysis, Henderson found that potassium-rich glass was used farther west (in Ireland) and at an earlier time (ninth- to seventh-century BCE) than previously thought.  These and other compositionally unusual samples are placed in a technological context with other ancient glasses.  In particular, he points out a new compositional category of British Iron Age glass that his work revealed.

    Hallett et al. (1988) utilized EMPA to investigate the materials and methods used to decorate ten distinct types of medieval Islamic ceramics from North Yemen.  One primary goal of the Yemen Archaeological Project was to establish the interaction of a medieval Islamic university town with its neighbors and the rest of the world.  There had been no earlier systematic archaeological research in the area, so an initial survey involved the surface collection of sherds to formulate a regional ceramic typology.  Over 2400 sherds were collected and first sorted by color, shape, and surface decoration treatment.  To refine these classifications, EMPA was utilized to identify the decorative components (glaze, paint, slip, etc.) and to find their compositions.  They claim that “consistency of composition among different types could indicate contemporaneity” over six centuries (266).  It was concluded that an intricate ceramic industry existed in North Yemen and that a wide assortment of decorative ceramic types were manufactured using a set of four basic fabrication techniques.

    Yener and Vandiver (1993) used EMPA to investigate tin processing at an early Bronze Age site in south-central Turkey.  They studied slags, surface residues, and earthenware refractories that were recovered from a workshop and habitation assemblage, which included groundstone tools, ore nodules, molds, and metal fragments as well.  Analyses of bowl-shaped crucible sherds indicate tin was secured by reduction firing of tin oxide in crucibles.  In fact, cassiterite, the mineral form of tin oxide, was detected on the interior of the crucible fragments.  Their results directly address several important issues about tin sources in Anatolia in the third millennium BCE.

    Verità et al. (1994) consider electron microprobe analysis of ancient glasses.  They maintain that “chemical analysis of ancient glassy materials, such as glass artefacts, glazes and enamels, can reveal important information for the classification and history” of glass technologies (241).  EMPA is “increasingly adopted” for the analysis of ancient glass due, in part, to its “ability to distinguish and analyse, or exclude, inclusions, opacifiers, and weathered areas” (241).  Verità et al. found that electron microprobe analyses, using both ED and WD spectrometers, “can produce reliable results which are adequate for most technological questions” about ancient glass (241).

    In 1995, a mica serpent cut-out from a Hopewell site, a part of the collection of the Peabody Museum of Archaeology and Ethnology, was sent to the Museum’s conservation lab.  This serpent is fashioned from muscovite mica, and since mica tends to exfoliate, several sheets of material likely have been lost over the years.  Curators found that a restoration in the 1920s was incomplete and its accuracy questionable.  Various mica cut-outs in the Museum’s collection show evidence of having once been painted with black, white, red, and yellow.  Accretions on this serpent are similar in color to red pigment on other mica cut-outs.  Electron microprobe analysis was conducted to compare the paint samples on other cut-outs and accretions on the serpent.  It was hoped that the analyses would reveal if these accretions were paint remnants.  Iron oxide, a prominent constituent of anhydrous red ochre, was present only at a very low concentration, which suggests that the reddish accretions most likely were clay left from its burial, not an intentionally applied pigment (Peschken 2002).

    Spurr (1995) analyzed the igneous rock temper in Emery Gray ceramics from Central Utah.  She reports that several different tempers are readily apparent, using a petrographic microscope, in this ceramic type.  Microprobe analyses of Emery Gray sherds from one Fremont culture site were used to address questions about the sources of these different tempers.  The EMPA results indicate that feldspars in two temper types are similar in composition.  Spurr also analyzed potential sources near that site, and she found that feldspars in the source samples were also similar in composition to those in the tempers.  She did find patterns in the temper compositions and the distributions of their source rocks.  Spurr asserts that these patterns might be used to establish the production location of these ceramics, determine exchange patterns, and refine their classifications.

    Boston (1995) used an electron microprobe to analyze volcanic ash in Sunset Red ceramics.  The Sunset Crater volcano in Arizona erupted around 1065 CE, and the occurrence of volcanic ash- tempered ceramics at a site is often taken as evidence that it was inhabited by the Sinagua after this eruption.  Likewise, an absence of ash-tempered ceramics at a site is taken as an indicator that it was occupied before the Sunset Crater eruption.  This presumes that Sunset Crater was the only source of volcanic ash available to Sinagua potters.  Boston analyzed some ash from Sunset Crater, and the analyses revealed compositional differences between the most recent ash layer and ash from earlier eruptions.  Ash-tempered Sunset Red ceramic samples were analyzed as well, and Boston identified chemical differences between samples.  Many of his samples were tempered with ash from the most recent eruption.  One sherd, however, appeared to be tempered with ash from an earlier eruption, and one contained ash from an unidentified source.  He concludes that non-Sunset Crater ash was used as temper, and he disputes that Sunset Red is an exclusively post-eruption ware.

    Owen and Hansen (1996) analyzed eighteenth-century British porcelain sherds from Nova Scotia and New Brunswick, Canada with an electron microprobe.  They state that the compositions of the sherds supplied clues about their origins.  Four of these sherds were rich in magnesium and lead, two of which contain a mineral not known in Worcester porcelain.  They attribute these sherds to an imitator of Worcester.  Three other sherds were rich in phosphate, only one of which could be attributed to a particular manufacturer.  Their intent is to refine chronologies of archaeological sites, and Owen and Hansen assert that “the sacrifice of a tiny fragment required for the analysis of each sherd was well worth the information that ultimately was gained” (99).

    Summerhayes et al. (1996) utilized EMPA to identify the microscopic mineral inclusions in Cypriot Bronze Age pottery.  Their aim was to investigate the ceramic technology and clay selection in the Early and Middle Bronze Age.  It has been hypothesized that potters chose clays based on the intended use of the final product.  Consequently, they arranged their research to test this hypothesis about ceramic manufacture.  They assert that a significant problem “in the use of ceramic chemical characterization concerns the effect of mineral inclusion on elemental concentrations” (175).  These inclusions in clay can either occur naturally or as artificially added temper.  If one does not account for the addition of tempers, it “will result in erroneous models of production and exchange” (175).  They concluded all of the mineral inclusions are found in local geologic formations, which suggests that all but one of the ceramic wares examined were produced locally.

    The next year, Summerhayes authored an article entitled “Losing Your Temper: The Effect of Mineral Inclusions on Pottery Analyses.”  He used EMPA and PIXE to analyze pottery from an island of Papua New Guinea.  He echoes warnings from the earlier article, claiming that analyses of ceramics are not straightforward due to naturally and artificially occurring inclusions.  Summerhayes asserts that the electron microprobe is “a useful tool in overcoming the problem of chemical noise” due to inclusions and therefore may lead “to the identification of production and exchange patterns which archaeologists can used in modelling the past” (108).  EMPA of two different pastes refined ideas about ceramic production and technology on this island.  The two pastes came from the same clay, and the compositional differences were due to the addition of temper.  He concludes that, since the “pastes come from wares that are temporally and stylistically identical,” it can be proposed that either two production centers exploited the same clay source, that clay was distributed by one center to another, or that a single production center utilized two different tempers (115).

       Rösch et al. (1997) state that “during the last three or four decades, X-ray power diffraction and electron microprobe analysis have become common tools” in materials and geological sciences while their use in archaeology “is still more or less sporadic” (763,764).  In particular, they assert microprobe analyses “can contribute to the unequivocal identification of ancient objects that cannot be worked out by archaeological investigations alone” (764).  Their work involves characterization of pre-Islamic beads from Oman and from old Signhalese kingdoms in Sri Lanka.  These beads are fashioned from ultramafic rocks, garnet, glass, gold, and synthetic enstatite.  Their aim is to learn the provenance of the beads and the methods of their manufacture.  They state that archaeometallurgists “have used electron microprobe analysis as a well established method for their investigations” for some time now, and Rösch et al. believe that it will soon be “a common tool for systematic work on various archaeological objects like beads, seals, small fibulas, or coins” (781).

    Mallory-Greenough et al. (1998) consider the origin of temper in a New Kingdom Egyptian sherd.  The researchers used petrologic (rock-based) and mineralogic (mineral-based) observations of the temper.  The composition of the clay itself implies a local source, but the sample is tempered with sand-sized rock fragments.  Their electron microprobe analyses demonstrated that minerals in these fragments have compositions common to mafic igneous rocks.  Their element ratios attest that crystallization occurred at 1100° C.  Sources for such material are few in Egypt.  Basalts in the area of Cairo are the most likely possible source.  They propose that a Cairo provenance for the sherd is consonant with the trade network between Memphis and Thebes on the Nile.  

    Weisler and Clague (1998) utilized EMPA to characterize sources of obsidian and artifacts from the Hawaiian islands.  They maintain that the distribution of archaeological obsidian can reveal scale, complexity, and duration of interaction among prehistoric societies of the islands of Oceania (103).  They assert that EMPA “is especially well-suited to... these specimens since only the glass itself is analyzed by excluding phenocrysts and other inclusions” (114).  Weisler and Clague chose two plots -- titanium vs. magnesium and calcium vs. titanium -- to highlight chemical differences and found the compositions of most samples, when plotted, fell “in a tightly defined array that overlaps the array defined by unaltered lava and glass samples from West Moloka’i, indicating that they are from West Moloka’i” (121).  Ultimately, they concluded that 50 artifacts from six habitation sites originated from nine West Moloka’i outcrops (122).  About 70 percent of the artifacts derived from three sources, and 47 percent came from the source nearest the sites.  Their results were unexpected, but different settlement patterns and occupation periods could account for the pattern.

    Neff et al. (1999) employed EMPA and neutron activation analysis to shed new light on the relationships among ceramic traditions of southeastern Mesoamerica.  Their analyses indicate Ivory ware, a Late and Terminal Formative ceramic style of southern Guatemala, differs chemically from a number of other Guatemalan light firing wares.  Instead, it was found to be similar to Formative and Classic cream paste wares of El Salvador and Honduras.  They deduce that the source for the wares is western El Salvador, not Honduras or Guatemala.  This refutes earlier hypotheses that Ivory ware came from the Guatemala highlands and cream paste wares from the Copan Valley.  These findings suggest that ceramic trade during the Late and Terminal Formative periods was more extensive than previously surmised.  It also implies that, in the Classic period, the Mayan city of Copán, in western Honduras, nearly monopolized ceramic production in western El Salvador.  

    Cotkin et al. (1999) examined utilitarian vessels recovered from eighteen Early Woodland to Fort Ancient period (1150 BCE to 1300 CE) sites in south-central Ohio.  They found that a portion of the samples had unpigmented slips and washes.  Such surfaces were discovered on vessels from all 23 dated components and throughout the sequence, including the earliest Early Woodland, when ceramics first emerged in the Midwest.  The archaeological literature, however, attests that uncolored slips and washes are unknown for utilitarian vessels of the prehistoric Eastern Woodlands.  Further, slips appear entirely unknown in the Early Woodland, and slips or washes in the pre-Mississippian Midwest are reported infrequently.  They utilized EMPA to analyze seven sherds and found that the bodies and slips were similar in composition, which implies that they were made from the same raw clay, without sieving or the addition of temper.  Coatings of calcite and apatite on these vessels were also analyzed with EMPA, and their results show that ceramic technology in the American Midwest and Southeast could have been more continuous than was previously suspected.

    Shriner and Dorais (1999) used EMPA to analyze ceramic artifacts as well as local clay-rich sediments and lithics in order to address questions about the nature of the cultural shift indicated by ceramics from the Lerna archaeological site in Greece.  This research is based on the fact “[m]ineral identification and textural descriptions of particle size, distribution and shape of minerals present in ceramic artefacts have acted as a predictive tool for local versus non-local production” (25).  They claim, however, that the absence of geological reference samples has made it difficult to determine whether ceramics are local, regional, or imported.  Shrine and Dorais analyzed a series of sediments that represents clays and temper materials for the area around the site, and these compositions were compared to those of the sherds.  They deduce that, while potters from Phases III and IV fashioned stylistically distinct wares, they likely procured clays and tempers from the source.

    Klockenkämper et al. (1999), using an electron microprobe, studied the surface enrichment of silver on Roman silver coins.  ED analyses were used to examine the uppermost layers (around 3 microns in depth) of 218 Roman coins.  Silver and copper were found to be major components, and 18 minor elements were detected and quantitatively measured.  They found that the enrichments and inhomogeneities increased in the second century and further increased in the third.  Klockenkämper et al. also discovered large variations in silver content and enrichment in coins for the same emperor, which is ascribed to different degrees of abrasion after their decades in circulation.