Use Of Quartz Research Articles

La Disponibilidad de cuarzo apto para la talla en las Sierras Pampeanas Australes

This paper presents the results of the study on the availability and use of quartz suitable for flintknapping in the Ongamira Valley (Córdoba, Argentina. At the archaeological sites studied—which correspond to late Holocene hunter-gatherer groups (ca. 1900-3600 BP)—more than 90% of the lithic assemblages were quartz. Researchers articulated different analysis techniques (remote sensing, prospecting, XRF, XRD and petrographic analyses) to understand the origin and local availability of this raw material. The results reveal the location and abundance of the primary quartz sources, estimate the material quality, and help us comprehend the variability between sources. Based on the data, the paper proposes a methodological model for discussing quartz use in the mountainous regions of Central Argentina and its integration into interpretations of human mobility circuits.

The secret is quartz: technology of production of an eleventh-twelfth century western Mediterranean polychrome glazed ware

A group of a well-known polychrome glazed ceramic, widespread in the western Mediterranean in the eleventh and first half of the twelfth centuries, has been analysed for the first time using Optical Microscopy (OM) and a Field Emission Scanning Electron Microscopy (FE-SEM) with Energy-Dispersive X-ray Spectroscopy (EDS), in order to shed some light on the materials, production technology and provenance, about which there are various hypotheses. This ware is characterised by a perfectly drawn and varied iconography, with often stylised zoomorphic and anthropomorphic and nautical motifs. It was produced in an as yet unidentified workshop in North Africa or the Iberian Peninsula. The pottery analysed was found in an archaeological excavation in the Barrio Andalusi of Almería (south-east of Spain). Technologically, the ceramics are fairly homogeneous, with copper-green and manganese-brown pigments applied over the raw tin glaze filled with large undissolved quartz particles. The use of quartz is consistent with a Fatimid-Zirid contribution from Ifriqiya, the use of tin is consistent with an Andalusi Umayyad-Taifas contribution, and the green and brown colours on a white ground to either Ifriqiya or Andalusi. Our study has shown that the use of quartz on the decorated glazed surface is not related to the need for an opacifier, but rather to the need for a highly viscous melt that limits the spread of the pigments during the firing allowing a finer and more detailed drawing. This fusion of different techniques has been identified for the first time. It is intriguing from the historical point of view of medieval technology, and provides the first insights into understanding the technological transfers and technical solutions that took place in the Mediterranean basin during this period.

Application of Proxy Minerals for Evaluation of the Oxygen Isotope Composition of Felsic Melts

The problems associated with the use of quartz and zircon as proxy minerals for the reconstruction of δ18O values in acidic melts are considered. It is shown that the correction values Δ(Qz–R) and Δ(R–Zrn) used for the reconstructions are not strictly constant and depend on the mineral composition of the rock and the closure temperature of the oxygen isotopic system of the proxy mineral (Tq, Tz–closure temperature of quartz and zircon, respectively). The applicability of quartz was estimated using an equation for Δ(Qz–R) calculation, which takes into account Tq and the mineral composition of rocks. Using the leucogranites of the Raumid massif (South Pamirs) as an example, it was shown that this correction can be approximated by constant value only under definite conditions. The value of Δ(R–Zrn) was estimated using approach based on calculating the weighted average fractionation coefficient and independent estimates Tz using a zirconium thermometer. It was shown for leucogranite porphyries of the Omsukchan trough that this correction for identical rocks varies from 1.3 to 1.9 ‰, unlike Δ(R–Zrn) = 2.1 determined by the dependence on the SiO2 content (Lackey et al., 2008). The advantages and limitations on the application of quartz and zircon as proxy minerals have been analyzed.

On the Application of Proxy Minerals for Evaluation of the Oxygen Isotope Composition of Acid Melts

The problems associated with the use of quartz and zircon as proxy minerals for the reconstruction of δ18O values in acidic melts are considered. It is shown that the correction values Δ(Qz-R) and Δ(R-Zrn) used for the reconstructions are not strictly constant and depend on the mineral composition of the rock and the closing temperature of the oxygen isotopic system of the proxy mineral (Tq, Tz). For Δ(Qz-R), an equation for the calculation is proposed, taking into account these factors, and it is shown that, under a number of conditions, the approximation of this correction by a constant value gives consistent results. To estimate Δ(R-Zrn), an approach has been proposed that consists in calculating the weighted average fractionation coefficient and estimating Tz using a zirconium thermometer. An analysis of the advantages and limitations of the use of quartz and zircon as proxy minerals has been carried out.

Development of a Quartz-Based Photo-Mobile Polymer Film for Controlled Motion Triggered by Light or Heat.

We have developed a photo-mobile polymer film, that combines organic and inorganic materials, to allow for controlled motion that can be triggered by light or heat. Our film is made using recycled quartz and consists of two layers: a multi-acrylate polymer layer and a layer containing oxidized 4-amino-phenol and N-Vinyl-1-Pyrrolidinone. The use of quartz in our film also gives it a high temperature resistance of at least 350 °C. When exposed to heat, the film moves in a direction that is independent of the heat source, due to its asymmetrical design. Once the heat source is removed, the film returns to its original position. ATR-FTIR measurements confirm this asymmetrical configuration. This technology may have potential applications in energy harvesting, due to the piezoelectric properties of quartz.

The in-depth study of Romanian prehistoric ceramics: Late Neolithic/Eneolithic pottery and clay materials from the Foeni Tell-Orthodox cemetery in Timiş county

The study aims to analyze pottery samples from the archaeological site Foeni Tell – Orthodox Cemetery, a late Neolithic & early Eneolithic multi-stratified site (three phases, covering the period 4720-4457 cal BC), also inhabited during the Early Bronze Age and Middle Ages. The site is located on the western edge of Foeni (Timiș county, Romania), on the eastern bank of the Timișaț river. The analyzed samples come from 20 pottery shards, belonging to the Foeni cultural group (4920/4675–4580/4460 cal BC, corresponding to the later period of the Vinča culture, from the end of phase C to the end of phase D), and are representative of the categories (black, red, orange, painted) and types (fine, semi-fine, coarse) pottery associated with the cultural group; also analyzed were soil samples from the site. Complementary techniques were used in the analysis (TG/DTG, FT-IR, SEM, EDX, XRF, XRD and LIBS) to ascertain details regarding production technology and origin of the raw materials used in making the pottery. Results indicate the pottery was based on a high plasticity illite and montmorillonite paste, alongside albite, microcline, analcime, with heavy use of quartz and mica as temper. The clay composition shows an obvious link between the pottery and the local sampled source, implying the local production of Foeni type pottery. The firing temperature is uniform in Foeni pottery, estimated in the range of 550–600 °C, with a maximum firing temperature of 600 °C, with slightly higher temperatures for painted wares, of up to 620–630 °C, with a maximum temperature of 650 °C. The sole exception has an estimated firing temperature in excess of 900 °C.

The use of quartz by ancient societies in the Serra de Carajás, Amazon, Pará

Resumo Este artigo tem como objetivo principal apresentar os resultados das análises realizadas nas indústrias sobre quartzos presentes nas coleções de dois sítios arqueológicos – Capela e Ananás –, localizados na região de Carajás, sudeste do estado Pará, Brasil. O método aplicado compreende a análise tecnológica, e o principal conceito utilizado é o de cadeia operatória, desenvolvido pela Escola Francesa e adaptado para este trabalho. Através dos resultados obtidos, foi possível observar as escolhas e as intenções dos antigos grupos humanos quanto ao gerenciamento destas matérias-primas, quais sejam, principalmente, pequenas lascas alongadas produzidas, pouco espessas, frequentemente utilizadas sem grandes transformações, debitadas por percussão direta dura e percussão sobre bigorna.

Optic properties of ZnO films grown by sol-gel technique

Background. Zinc oxide (ZnO) is a promising material for designing the semiconductor radiation sources and detectors in the region of short wavelengths of the optical range. Films based on ZnO are considered as possible elements of optoelectronic devices that can be used to influence their optical properties. Nowadays, the methods of making such films are quite diverse, however, obtaining high-quality and inexpensive ZnO films remains an actual scientific and engineering task that needs to be solved. Thus, the research in this direction and the development of recommendations on the synthesis of ZnO films is urgent. Purpose of Work. The aim of the work is to obtain ZnO films by the sol-gel technique, to evaluate their structure and optical properties and to estimate the affect of ultraviolet radiation on the structure and optical characteristics of the obtained films. Techniques and Methodology. The process of obtaining ZnO films is considered. The process of obtaining such films by sol-gel technique is described. A visual analysis of the experimentally obtained films has been carried out. The optical properties of ZnO films were experimentally examined. In particular, the influence of ultraviolet radiation used at the stage of obtaining films on the features of their ability to absorb radiation in the optical range is analyzed. Results. ZnO films were grown experimentally by sol-gel technique. ZnO films were formed on quartz substrates. The formation of ZnO nanoparticles is observed in the films obtained without the influence of radiation. The usage of ultraviolet radiation at the stage of the final heat treatment at a temperature of 480 °C leads to the formation of a higher quality ZnO film and a decrease in the size of the granules. Analysis of the chemical composition of the films using X-ray fluorescence analysis shows the presence of zinc and oxygen in the formed films, as well as insignificant carbon content, which is associated with the use of quartz as substrates. The dependencies of the transmission capacity of ZnO films on the wavelength of radiation incident on the film in the range of 200-450 nm are obtained. It is shown that in films exposed to ultraviolet radiation at the stage of heat treatment, there is a shift in the value of the cut-off wavelength corresponding to the absorption edge and, accordingly, a decrease in the band gap calculated from the results of the experiment. Conclusions: To summarize the results of the research we can highlight that the influence of ultraviolet radiation at the stage of the final heat treatment on ZnO films formed by sol-gel method leads to an improvement in the quality of the films and to a change in their optical properties, in particular, a decrease in the energy corresponding to the absorption threshold.

The Gravettian-Solutrean transition in westernmost Iberia: New data from the sites of Vale Boi and Lapa do Picareiro

This study presents the analysis of the lithic assemblages from Layers 5 and 4E (Terrace) of the site of Vale Boi (southern Portugal) and Levels U and T from Lapa do Picareiro (central Portugal). We aimed to understand the technological patterns and raw material exploitation during the Gravettian-Solutrean transition in westernmost Iberia and test the traditional models with assemblages from recently excavated sites, while expanding the geographic range. Results show the existence of two discrete phases in each site. The first, with high frequency of quartz use for bladelet production, seems to reflect the presence of a Terminal Gravettian horizon, as defined by Almeida (2000). The second, with some significant differences between sites, attests the presence of Vale Comprido technology and lower quartz frequencies at Vale Boi, representing a Proto-Solutrean occupation; and the presence of a blade component in Lapa do Picareiro that, together with the respective absolute chronology, may be attributed to a Proto-Solutrean or an Early Solutrean horizon. In general terms, this study allowed to confirm that the Terminal Gravettian and the Proto-Solutrean are discrete phases across the transition, in agreement with the Three-Phase model presented by Zilhão (1997). It further consolidates the expansion of similar techno-cultural patterns to southern Portugal, which may be explained by the significant changes in the dynamic of social networks (Cascalheira and Bicho, 2013).

Tracking ancient people movements in the Southern Pampean Hills of Argentina by XRF, XRD and SEM on quartz lithic technology: a preliminary report

Quartz-based hunter-gatherer lithic technology is present around the world. It occurs particularly where the Precambrian crystalline basement outcrops, including South Africa, Northern Europe, North America and large areas of South America. However, little effort has been made to try to characterize its chemical composition to help understand either mobility strategies or exchange networks. We report here the results of a preliminary methodological approach comparing the chemical characterization of quartz from archaeological sites (quarries and residential types) and geological sources through different techniques: X-Ray Fluorescence, X-Ray Diffraction, SEM and EPMA analyses. The detection of trace elements from quartz outcrops and its comparison with artifacts from residential archaeological sites from the Ongamira valley (a mountainous region of Central Argentina) was undertaken in this work. The archaeological samples came from layers radiocarbon-dated to the Late Holocene (between ca. 3600 BP to 3000 BP) and are related to nomadic hunter-gatherer societies where the use of quartz for technology was predominant (representing more than 90 percent of the tools and debris in each archaeological site). As a result of the comparison, it was possible to establish positive or negative relationships between some of the quartz samples from the residential locus and the geological sources. Some results showed that the nearest quarries to the residential sites were not used at the residential camp. On the other hand, it was also possible to establish that non-local quartz outcrops located far away from the Ongamira valley were not present at any of the Ongamira sites. This shows us that rock procurement was oriented to the selective use of local raw material and therefore a low-range mobility strategy. Finally, it may be related to better local environmental conditions in the Late Holocene, when people did not need to travel so far for other resources or purposes.

Actuator Based on a Dielectric Elastomer with Quartz as a Filler for Vacuum Technology

Modern equipment requires precise movement of objects both at atmospheric pressure and in vacuum conditions. Moreover, vacuum equipment is subjected to a number of external disturbances that adversely affect the manufacturing process and have a direct impact on the quality of manufactured products. A promising development in this area is actuators based on dielectric elastomers, characterized by a short reaction time (milliseconds) and a simple and cheap implementation. Successful implementation depends on an understanding of its behavior and properties, depending on the choice of matrix and filler materials. Most often, expensive barium titanate is used as a filler. This paper discusses the use of quartz as a cheaper filler.

Comparison of AlN vs. SIO2/LiNbO3 Membranes as Sensitive Elements for the SAW-Based Acceleration Measurement: Overcoming the Anisotropy Effects.

We propose the use of aluminum nitride (AlN) membranes acting as sensitive elements for the surface acoustic wave (SAW)-based acceleration measurement. The proposed solution is compared against existing prototypes based on the use of quartz (SiO2)/lithium niobate (LiNbO3) membranes that are characterized by extensive anisotropic properties. Using COMSOL Multiphysics 5.4 computer simulations we show explicitly that sensitive elements based on less anisotropic AlN membranes overcome both the low sensitivity limitations of SiO2 and low temperature stability of LiNbO3. Moreover, AlN membranes exhibit nearly double the robustness against irreversible mechanical deformations when compared against SiO2, which in turn allows for further 1.5-fold sensitivity enhancement over LiNbO3 based sensors. Taking into account their acceptable frequency characteristics, we thus believe that the AlN membranes are a good candidate forsensitive elements especially for high acceleration measurements.

Understanding Neanderthal technological adaptation at Navalmaíllo Rock Shelter (Spain) by measuring lithic raw materials performance variability

Navalmaillo Rock Shelter is an Upper Pleistocene archaeological site in the Lozoya River Valley (Madrid, Spain) with a quartz-based Mousterian lithic assemblage. To understand the reasons behind an intense use of quartz over flint and quartzite, a mechanical experiment was carried out. Flakes from flint, quartzite, and local quartz were tested under controlled conditions and quantifiable variables. The mechanical action consisted in a standardised linear repetitive cutting protocol over antler and pine wood. Results allowed to differentiate flake resistance between raw materials through mass and edge angle material loss statistics. Results also showed that the edges produced on flint are sharper allowing to create deeper cuts, but the thin working edges break more easily meaning that they would need a higher maintenance by retouch. Quartzite and quartz have similar performances, but quartzite suffers a more intense modification of the edge angle, while quartz edges present a higher endurance. When compared with flint, quartzite and quartz are more suitable for those tasks where heavier force is applied. Based on that, we concluded that there was no functional disadvantage in using a quartz-based toolkit. Therefore, the quartz assemblages recovered throughout the sequence of Navalmaillo Rock Shelter show that it was intensely explored not just because of its availability in the landscape but also for its suitability to the development of the different activities taking place at Navalmaillo Rock Shelter such as big sized herbivore butchering, for a long time span.

Assessment of Granite, Quartz and Syenite Aggregate Suitability Intended for the Application in Case of Transport Pavement Concrete

Based on the analysis of the obtained laboratory test results, the article presents the suggestion concerning the use of quartz and syenite aggregate as granite aggregate alternative, in the composition of cement concrete intended for airfield pavements. The scope of laboratory tests with regard to rock materials included the assessment of basic properties of the applied aggregates and their influence on the change of parameters of internal structure of hardened cement concrete. The analyses included evaluation of the selected aggregate parameters, i.e. bulk density, absorbability, sand equivalent, abrasion, crushing and polishing resistance. The influence of the applied materials on the change of the basic physical properties (bulk density and absorbability) was specified and mechanical parameters (compressive, splitting tensile strength and bending strength) of the curing concrete within diversified periods. According to the observed changes in the internal structure of concretes, the influence of the aggregate type on the obtained parameters of hardened concretes and their airfield pavement application were determined.

Recycling of shards of quartz ceramic shells from investment casting

The use of quartz for its low-temperature modification creates additional risks in the manufacture of molds in the part of their reduced crack resistance due to polymorphous transformations and in practice it often leads to cracking and even destruction of individual layers of the shell wall or the mold as a whole. Preliminary calcination of the covering material practiced in many foundries can somewhat reduce the negative consequence of dangerous polymorphic transformations of quartz. But at the same time, smooth heating of the molds to reduce the likelihood of their cracking, which is carried out in the support filler, contributes to an increase in duration of the technological process and in additional energy costs. Among the options for reducing the likelihood of cracking and the destruction of RP during their calcination, the most popular is replacement of pulverized quartz sand, as filler, with dispersed quartz sand of a polyfraction composition, disten-sillimanite, pulverized aluminosilicate, spherical corundum or fused quartz. However, all of them are quite expensive and do not meet modern challenges and resource saving requirements in foundry and metallurgical industries. In this connection, attention is drawn to the ceramic shards of shells of steel and aluminum investment casting on silica-based models. At present, the shards of spent ceramic shell molds for investment models is not used for recycling. This material is sent to the dump or used as a supporting filler of the flasks when the shells are formed therein. The conducted component chemical and phase analysis of the material has shown that in shards of ceramic shells formed after knocking out steel and aluminum castings from molds, in addition to quartz in the high-temperature phases of tridymite and cristobalite (base), there are up to 5 - 10 % of iron and iron scale and 3 - 5 % of aluminum and its oxides. The use of ceramic shell shards as a covering material excludes the repeated polymorphic quartz transformations during calcination and pouring of shapes that determine the change in volume, density, and change in types of material crystal lattices, which makes it possible to increase the fracture toughness and strength of the shells and to minimize discard of the resulting castings. Residual iron, aluminum and their oxides contribute to improving the processability of the mold. Experimental testing of the proposed recycling option in the conditions of current production has confirmed its effectiveness.

Lithic technological responses to Late Pleistocene glacial cycling at Pinnacle Point Site 5-6, South Africa

There are multiple hypotheses for human responses to glacial cycling in the Late Pleistocene, including changes in population size, interconnectedness, and mobility. Lithic technological analysis informs us of human responses to environmental change because lithic assemblage characteristics are a reflection of raw material transport, reduction, and discard behaviors that depend on hunter-gatherer social and economic decisions. Pinnacle Point Site 5–6 (PP5-6), Western Cape, South Africa is an ideal locality for examining the influence of glacial cycling on early modern human behaviors because it preserves a long sequence spanning marine isotope stages (MIS) 5, 4, and 3 and is associated with robust records of paleoenvironmental change. The analysis presented here addresses the question, what, if any, lithic assemblage traits at PP5-6 represent changing behavioral responses to the MIS 5-4-3 interglacial-glacial cycle? It statistically evaluates changes in 93 traits with no a priori assumptions about which traits may significantly associate with MIS. In contrast to other studies that claim that there is little relationship between broad-scale patterns of climate change and lithic technology, we identified the following characteristics that are associated with MIS 4: increased use of quartz, increased evidence for outcrop sources of quartzite and silcrete, increased evidence for earlier stages of reduction in silcrete, evidence for increased flaking efficiency in all raw material types, and changes in tool types and function for silcrete. Based on these results, we suggest that foragers responded to MIS 4 glacial environmental conditions at PP5-6 with increased population or group sizes, ‘place provisioning’, longer and/or more intense site occupations, and decreased residential mobility. Several other traits, including silcrete frequency, do not exhibit an association with MIS. Backed pieces, once they appear in the PP5-6 record during MIS 4, persist through MIS 3. Changing paleoenvironments explain some, but not all temporal technological variability at PP5-6.

Techno-economic human behavior in a context of recurrent megafaunal exploitation at 1.3 Ma. Evidence from BK4b (Upper Bed II, Olduvai Gorge, Tanzania)

Taphonomic analysis carried out at BK4b has provided compelling evidence for megafaunal acquisition and consumption, and the amount of meat that hominins consumed is far greater than documented at any other early Pleistocene site. The aim of the present work is to characterize the lithic assemblage associated with such a special subsistence context. The results presented here show that the bulk of the technological process was largely devoted to producing in-site small quartz flakes motivated by an imperative demand for durable cutting edges. Conversely, the operational sequence aimed at producing LCTs played a secondary role and is represented by different and isolated fractions. The quality of the cutting edges of quartz flakes may explain the preferential use of quartz at BK4b for flake production. These techno-economic strategies are likely connected with the exploitation and consumption of carcasses (butchering technology), but other subsistence activities were carried out besides butchery. In sum, we can conclude that the higher demand of cutting edges that presumably required a recurrent megafaunal exploitation at BK4b was largely satisfied by the production of small flakes rather than LCTs.

Innovation and tradition in the fourth century mosaic of the Casa delle Bestie Ferite in Aquileia, Italy: archaeometric characterisation of the glass tesserae

The present paper focuses on the archaeometric characterisation of 38 glass tesserae of various colours from an in situ mosaic in Aquileia, Italy, dated to the second half of the fourth century AD. The examination of the textural, mineralogical and chemical features, conducted by means of a multi-methodological approach (optical microscopy (OM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), electron probe micro analysis (EPMA), X-ray diffraction (XRD) and Fibre Optic Reflectance Spectrophotometer (FORS)), has provided valuable insights into the changes in the production technology during the transition between the Roman and the Late Antique periods. The assemblage is heterogeneous, and each chromatic group is composed of tesserae produced with different base glasses and colouring/opacifying techniques, suggesting diverse supplies. A small group of tesserae shows strict links to the Roman tradition in terms of both base glass and colouring/opacifying techniques and was probably obtained by re-using tesserae from older mosaics. Conversely, a larger group of tesserae shows textural and chemical evidence of recycling and indicates the prompt use of “new” opacifying technologies (such as the use of tin compounds) or uncommon technological solutions (such as the use of quartz and bubbles as opacifiers or the addition of metallurgical slags in red tesserae), suggesting a specific production in the fourth century AD.

The use of quartz during the Lower Palaeolithic in northeastern Iberia

This article analyses the use of quartz as a raw material during the Lower Palaeolithic in the northeast of the Iberian Peninsula. We studied the use of quartz at 9 sites with chronologies ranging from the end of the Early Pleistocene to the end of the Middle Pleistocene. Quartz was used in all assemblages studied, and was always collected close to the sites, most of all in the form of pebbles from river basins. There was a differential selection of raw materials, including quartz, according to the technical strategy that humans wanted to implement. Despite the apparent simplicity of operational schemes carried out using quartz, we found factors that point to a remarkable conceptual complexity in the handling of this rock, as for example knowledge of the characteristics and mechanical possibilities of quartz, and the adaptation of operational schemes to the properties of this raw material.

The role of quartz in Neolithic lithic traditions: a case study from the Thornhill Early Neolithic palisaded enclosure, Co. Londonderry, Northern Ireland

The role of quartz in Neolithic lithic traditions: a case study from the Thornhill Early Neolithic palisaded enclosure, Co. Londonderry, Northern Ireland