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In this study, soapstone waste originated from craftsmanship activities was used as an alternative filler (0–30 wt%) for a high‐density polyethylene (PE) matrix. The aim of this paper is to understand the effect of the filler particles on crystallinity, thermal stability and thermo‐mechanical properties of this newly developed composite material. Physico‐chemical characterization was performed by x‐ray diffraction (XRD) and Fourier‐transform infrared (FTIR) spectroscopy. Thermogravimetric analysis (TGA), oxidation induction time (OIT) and dynamic mechanical thermal analysis (DMA) were performed to assess the effect of the filler on the themo‐mechanical properties of PE. Thermal stability, measured by TGA, was enhanced, while OIT values reduced with filler content. A significant increase on the storage modulus of the composites (up to 148% in comparison with unfilled PE) was observed and this reinforcing effect was even more prominent at higher temperatures. XRD analysis revealed that the degree of crystallinity improved significantly with soapstone loading, which explains the substantial increase in stiffness observed. Increased crystallinity is also associated with higher strength, reduced residual stress, and better dimensional stability of end products, which can be particularly attractive for pressure pipe applications. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyze a set of pietra ollare fragments that presented burnt encrustations to further understand the use of pietra ollare vessels during the Middle Ages. The fragments were obtained from Nogara (Vr) and date to the 9th–10th centuries CE. To obtain a variety of data, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) and pollen analyses were performed. The SEM-EDS enabled the microscopic observation and the understanding of the chemical composition of the encrustations; the pollen analysis was performed to find possible pollen trapped in the encrustations. The pollen was scarce, but notable specimens were found. The results SEM-EDS analysis provided data possibly linked to meat preparation. Further analysis will be conducted to deepen our understanding of the use of the pietra ollare in cooking practices. These results are relevant because they match other data that have emerged from the excavations at Nogara (archeozoological and paleobotanical) and because the use of this kind of vessel remains poorly studied.

The article focuses on the Intrusive Mound culture of the Midwest, which existed from 650 AD to 1000 AD, known for burying their dead in earlier Hopewell mounds. Topics include their distinctive artifacts, such as platform pipes, ceremonial stone picks, and Jack's Reef projectile points, and the cultural significance of these items in the context of burial practices and regional archaeology.

The aim of this study was to analyze a set of pietra ollare fragments that presented burnt encrustations to further understand the use of pietra ollare vessels during the Middle Ages. The fragments were obtained from Nogara (Vr) and date to the 9th–10th centuries CE. To obtain a variety of data, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) and pollen analyses were performed. The SEM-EDS enabled the microscopic observation and the understanding of the chemical composition of the encrustations; the pollen analysis was performed to find possible pollen trapped in the encrustations. The pollen was scarce, but notable specimens were found. The results SEM-EDS analysis provided data possibly linked to meat preparation. Further analysis will be conducted to deepen our understanding of the use of the pietra ollare in cooking practices. These results are relevant because they match other data that have emerged from the excavations at Nogara (archeozoological and paleobotanical) and because the use of this kind of vessel remains poorly studied. [ABSTRACT FROM AUTHOR]

In the Urals, there are more than a hundred products with large-diameter holes, some of which are made using a copper tube. Experiments on hollow drilling in the expedition of S. A. Semenov have shown great complexity of this method. In experiments on drilling it was planned to identify labor costs for the manufacture of copper tube, and also reveal various aspects of drilling techniques. The article presents the results of experiments on drilling different types of stone (soapstone, marble, serpentine and jade) with a copper tube. Experiments have shown that drilling with a brace is 1.5 times more effective than drilling with a borer. And using a copper tube as a drill increased the speed of making holes by 4–7 times. It also turned out that the abrasive used is very important for drilling efficiency. The most effective abrasive was emery, whose deposits are known in the southern Urals. The results obtained allow the authors to establish with great accuracy what drills and with application of what equipment stone axes of Bronze Age were drilled. A comparison of the experimental drills with bronze age drills shows that drilling with a copper tube was often, but not always, performed using a special machine tool. Labor-intensive making stone axes with large diameter holes especially made of strong row materials attest about high social status of their owners.

Abstract Background The hand-carved, traditional, versatile kitchen utensils made up of soft soapstone are used and treasured since the rise of civilization in India, especially in the southern states: Andhra Pradesh, Telangana, Tamil Nadu, Karnataka, and Kerala. They are called as rathi chippa and kal chatti and employed for cooking, serving, and storing food for many generations. Results The soft soapstone is chemically characterized as steatite and mainly composed of talc. The cookware of varying colors, shapes, and sizes are hand made by the artisans from Tamil Nadu state and offered for sale in the shops located in temple premises and during annual temple festivals. The delicate cookware requires proper conditioning and care while cooking, handling, and cleaning. Such inert cookware has positive quality properties such as low dielectric, high temperature resistance, high density and high mechanical strength. These characteristics have been reflected on the cookware application in cooking foods that require longer cooking time over a gentle fire, and sour, acidic, tamarind containing dishes. They are extensively used for making liquid, gravy-based curries and semi-solid foods; storing and preserving milk, curd, buttermilk, rock salt, tamarind, extracts, pickles, etc. Conclusions Notably, the food cooked in soapstone cookware retains the natural, authentic, original aroma and taste. As an insulator, it acts as a casserole by keeping the food hot for longer durations. Being extremely dense and non-porous, it is impervious to bacterial penetration and prevents the bacterial growth on the surface as well as extends the shelf life of cooked foods. Fascinated by traditional importance, distinct taste and health benefits, and tired of factory-made things, the current generations are shifting toward these handmade, exclusive soapstone products.

Title in English: Baptismal Fonts made of Scandinavian Rock in Sweden and Northern Germany The article provides an overview of the various types of rock used for baptismal fonts from the Middle Ages onwards in Scandinavia, especially Sweden and Northern Germany. The fonts are made of boulders as well as bedrock from these countries, and some of them were exported within the region. Some studies of the migration of both rocks and styles in order throw further light on the existence of trade routes, forms of cultural transfer, iconography and decorative features, and how they changed over the centuries, have been published in Scandinavia. The specimens described here serve only as examples of larger groups of fonts, which in most cases have both stylistic and petrographic characteristics in common. The author wants to encourage further research, especially in Germany, in order to ascertain such similarities for other types of rock as well, and at the same time look for deviating elements. The article is in German, with captions in English and a map indicating the locations of the fonts depicted.

The Finnish soapstone industry has found through practical experience that the surface of the magnesite soapstone used in fire chambers and funnels hardens over time. We have studied a magnesite soapstone used in a fireplace continuously for 60 years. The mineralogical changes, that took place during heating and subsequent cooling of the fireplace have been investigated with electron probe microanalyzer and X-ray diffractometer to find an explanation, what kind of reactions caused the hardening. We found that ferromagnesite has been altered to pseudomorphic aggregates composed of ferropericlase and magnesioferrite in the nearest ~30 mm from the surface exposed to fire. Iron has been mobilized in the uppermost 3 mm, enriched in the rims, and depleted from the cores of the ferropericlase aggregates. Magnesioferrite occurs preferably in the fire chamber side of the aggregates in the uppermost 0.20 mm. Talc rims are altered to forsterite and/or enstatite in the reaction with ferromagnesite or its alteration products in the uppermost ~1 mm. In addition, wood combustion gases caused considerable enrichment of zinc and potassium in the chamber surface rock to the depth on 0.20 mm and 3 mm, respectively. The enrichment occurred by crystallization of Zn bearing ferropericlase and magnesioferrite and by crystallization of K bearing sheet silicates.

In the article, the author presents the four miniature stone mace pendants that he curated. One pendant is made of greenstone and was found by John Tilley near the Tennessee River in Hardin County, Tennessee. Also cited are the pendant made of steatite and the pendant made of Dover flint, and the stone and ceramic miniature mace artifacts found in high status burial sites in Georgia, Alabama and Florida.

Engineered covers are commonly used to control the potential environmental problems related to acid mine drainage and contaminated seepage from tailings and waste rock storage facilities. Cyclical environmental weathering processes, such as freeze-thaw and wet-dry cycles, can cause rock degradation. However, these processes are usually not explicitly considered when selecting coarse-grained geomaterials for use as cover materials, even though they could be responsible for a decrease in cover performance over time. This study assesses the durability of a non-potentially acid-generating soapstone waste rock unit with respect to freeze-thaw and wet-dry cycles. This waste rock is intended for use as a cover material for the reclamation of mine tailings and waste rock storage facilities at a site in the Canadian Arctic. An experimental approach was developed based on existing standard and non-standard laboratory methods. Degradation tests were conducted on rock cores, rock slabs, and < 50-mm granular materials. These tests examined changes in selected physical and mechanical properties before and after 20 and 80 freeze-thaw and wet-dry cycles. The high density, low water absorption index, and low apparent porosity of the fresh waste rocks suggested excellent rock durability, which was confirmed by the degradation tests that showed acceptable mass losses and negligible evolution of the material's physical and mechanical properties over time. Considering the results of this study, the studied waste rock unit was identified as an excellent construction material for mine closure purposes. The experimental approach developed for this study could be included in cover design methodologies and applied widely in the selection of rocks for use in mine reclamation schemes in cold regions. [ABSTRACT FROM AUTHOR]

Title in English: Granite, Sandstone, Limestone and Soapstone. Danish Romanesque Baptismal Fonts and their Travels In Denmark Medieval baptismal fonts are mostly hewn in granite from erratic blocks and mainly form small groups originating from different “workshops”. However, some of the fonts were imported from Bentheim (Western Germany), Tournai (Belgium) and Southern Norway. A more substantial number came from the Baltic island of Gotland in Sweden. In Denmark baptismal fonts have sometimes been moved over considerable distances, mostly from Scania (part of medieval Denmark) to Zealand and even to Western Jutland. This paper discusses how and why such transport was organized. The rather extensive Scanian production of sandstone fonts seems to represent a general European tendency towards standardized mass production. This eventually led to a concentration of font manufacturing on 13th century Gotland, where suitable limestone was easily accessible and the products could be exported along established overseas traderoutes.

Natural rocks, as well as artificial man-made materials, undergo degradation caused by natural and man-made agents. Many pieces made of steatite that are part of magnificent monuments, listed as World Heritage Sites, are currently at an advanced level of degradation. Therefore, alternatives and actions are needed to interrupt this process and recover the deteriorated artefacts. In this context, this work aims to develop and characterise composite materials with the potential to repair surface wear, replace damaged parts and produce copies of sculptures made of soapstone. In order to produce materials with colour and texture similar to rocks, the powder residues of soapstone are used as a dispersed phase in the composites. Three different types of matrix materials (epoxy polymer, white Portland cement and pozzolanic Portland cement) are used in composites in order to identify the most suitable composition for restoration works. A statistical methodology based on the design of mixture is applied to identify the best matrix composition. Through this methodology, it is possible to investigate not only the behaviour of the different matrices that act independently but also the effect of the combination of these materials in several proportions. The physical and mechanical properties such as bulk density, apparent porosity, water absorption, compressive strength and elastic modulus are investigated. Composites made with 30% epoxy polymer and 70% steatite particles reach the greatest potential to be applied in restorations of historic monuments made of soapstone. These composites have properties superior to rocks and other composites, in addition to exhibiting texture and colouring similar to natural soapstone. [ABSTRACT FROM AUTHOR]

Background: The hand-carved, traditional, versatile kitchen utensils made up of soft soapstone are used and treasured since the rise of civilization in India, especially in the southern states: Andhra Pradesh, Telangana, Tamil Nadu, Karnataka, and Kerala. They are called as rathi chippa and kal chatti and employed for cooking, serving, and storing food for many generations. Results: The soft soapstone is chemically characterized as steatite and mainly composed of talc. The cookware of varying colors, shapes, and sizes are hand made by the artisans from Tamil Nadu state and offered for sale in the shops located in temple premises and during annual temple festivals. The delicate cookware requires proper conditioning and care while cooking, handling, and cleaning. Such inert cookware has positive quality properties such as low dielectric, high temperature resistance, high density and high mechanical strength. These characteristics have been reflected on the cookware application in cooking foods that require longer cooking time over a gentle fire, and sour, acidic, tamarind containing dishes. They are extensively used for making liquid, gravy-based curries and semi-solid foods; storing and preserving milk, curd, buttermilk, rock salt, tamarind, extracts, pickles, etc. Conclusions: Notably, the food cooked in soapstone cookware retains the natural, authentic, original aroma and taste. As an insulator, it acts as a casserole by keeping the food hot for longer durations. Being extremely dense and non-porous, it is impervious to bacterial penetration and prevents the bacterial growth on the surface as well as extends the shelf life of cooked foods. Fascinated by traditional importance, distinct taste and health benefits, and tired of factory-made things, the current generations are shifting toward these handmade, exclusive soapstone products. [ABSTRACT FROM AUTHOR]

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The late Archaic Soapstone Ridge quarries, near Atlanta, Georgia, are the largest sources of archaeological soapstone in the south‐eastern USA. Ten soapstone artefacts from the coastal plain, over 200 km south of Soapstone Ridge (SSR), were used in an attempt to relate their mineralogy to that of the Soapstone Ridge quarries and to investigate the utility of mineralogy in the sourcing of soapstone. There is an overall similarity in the abundance of the major soapstone minerals, talc, chlorite and amphiboles in the artefacts and the SSR soapstone. Differences in the variety of amphibole (tremolite/actinolite, magnesiohornblende and magnesiocumingtonite/anthophyllite) and FeTi oxides (magnetite and ilmenite) eliminate SSR as a source for some of the artefacts. The compositions of chlorite (Cr), magnesiohornblende (Si, Al) and Fe oxides (Cr, Mn) in other artefacts are not consistent with a Soapstone Ridge source. The talc compositions are identical in the artefacts and the SSR soapstone. The mineral assemblage and compositions of two artefacts are consistent with a Soapstone Ridge source. Despite an overall similarity in the modal mineralogy of the artefacts and Soapstone Ridge quarries, there is enough diversity to distinguish between artefacts from Soapstone Ridge or some other source. Mineralogy is a useful tool for the evaluation of soapstone sources. [ABSTRACT FROM AUTHOR]

The present study aims to explore the diversity patterns of cultivable filamentous fungi and establish the ecological interactions that occur within the mycological community on soapstone in two distinct places: Architectural Complex of Caraça and Congonhas town, in Minas Gerais state, Brazil. A total of 200 isolates of filamentous fungi were detected and 72 distinct taxa were identified using molecular tools. The rock-inhabiting fungal communities were comprised of cosmopolitan taxa, which displayed high diversity and richness, but low dominance indexes at two of the sampling sites over the course of 12 months. The detection of organic acids secreted by the isolated filamentous fungal species revealed the potential for deterioration of the model stone by these fungi. Our results suggest that the isolated fungal communities of the two Brazilian localities have the ability to adapt to environmental adversities over the four seasons of the year, predicting adaptive population dynamics in the stone colonization. We conclude that this study on the ecological dynamics of the rock-inhabiting fungal communities can help to understand the competitive interactions between the environmental fungi. In addition, these fungi may contribute to the preservation of the Brazilian historical heritage that is vulnerable to environmental conditions. [ABSTRACT FROM AUTHOR]

In the present work, transient CFD simulations of full wood log combustion cycles have been performed to study the time dependent behavior in cast iron and soapstone wood stoves. A model for the gas release is developed and implemented. The gas release model takes into account that the fuel gas release is transient, where both mass flow rate and gas composition as well as gas temperature changes with time. The effect of the wood stove material and its thermal inertia and conductivity on the combustion process and the transient heat release to the surroundings has been studied. In addition, transient variation in gas and wall temperatures as well as the combustion performance, was also studied. The simulations clearly show the effect of stove type on the transient heat release, which is controlled by the outer wall temperatures and the amount of heat transferred into the walls and their heat storage capacity. Due to the long real time duration of a full combustion cycle, these simulations are computationally very expensive and therefore only twodimensional simulations were performed. The results show that the cast iron stove has higher outer wall temperatures and heat release during the combustion cycle than the soapstone stove. The soapstone stove has flatter profiles for outer wall temperatures and heat release to the surroundings and have a longer heat release period after the combustion cycle has ended. [ABSTRACT FROM AUTHOR]

The Finnish soapstone industry has found through practical experience that the surface of the magnesite soapstone used in fire chambers and funnels hardens over time. We have studied a magnesite soapstone used in a fireplace continuously for 60 years. The mineralogical changes, that took place during heating and subsequent cooling of the fireplace have been investigated with electron probe microanalyzer and X-ray diffractometer to find an explanation, what kind of reactions caused the hardening. We found that ferromagnesite has been altered to pseudomorphic aggregates composed of ferropericlase and magnesioferrite in the nearest ~30 mm from the surface exposed to fire. Iron has been mobilized in the uppermost 3 mm, enriched in the rims, and depleted from the cores of the ferropericlase aggregates. Magnesioferrite occurs preferably in the fire chamber side of the aggregates in the uppermost 0.20 mm. Talc rims are altered to forsterite and/or enstatite in the reaction with ferromagnesite or its alteration products in the uppermost ~1 mm. In addition, wood combustion gases caused considerable enrichment of zinc and potassium in the chamber surface rock to the depth on 0.20 mm and 3 mm, respectively. The enrichment occurred by crystallization of Zn bearing ferropericlase and magnesioferrite and by crystallization of K bearing sheet silicates. [ABSTRACT FROM AUTHOR]

Soapstone industry utilizes different types of soapstone mainly as a construction material for fireplaces. In this application soapstone has to meet different temperature requirements in different parts of fireplaces. Mineralogical and structural information is needed for placing an appropriate type of soapstone in an appropriate position in the fireplace construction. This allows employment of higher temperatures resulting in more particulate-free combustion, which makes it possible for soapstone industry to develop more efficient and environmentally friendly fireplaces. Of many soapstone types, which differ from each other in their chemical composition and thermal properties, carbonate soapstone and its microstructural variations were investigated in this study. A new method was developed to measure thermal shock resistant of natural stones. By exposing carbonate soapstone samples of different textural types to rapid temperature changes, it was possible to determine the parameters that affect the capacity of the rock to resist thermal shock. The results indicate that the type of microtexture is an important factor in controlling the thermal shock resistance of carbonate soapstone. The soapstone samples with a high thermal shock resistance show deformation textures, such as crenulation cleavage and S/C mylonite. A strong negative correlation was observed between the thermal shock resistance and length of cleavage domains in foliated rocks. Also a slight elevation in the iron concentration of talc and magnesite was discovered to improve the thermal shock resistance of carbonate soapstone. Attention should especially be paid to the length and planarity of cleavage domains of spaced foliation.

The article offers information on Grey-Hardin Great Pipe. It mentions that after Joseph Malcolm Hardin had been diagnosed with terminal bone cancer, he sold the pipe and the rest of his collection to his longtime hunting friend Eldon Grey. It also mentions that effigy pipes are of animal or bird designs and are primarily made from a block of dark steatite of southeastern origin.

Abstract The organization of beadproduction during the Aurignacian has significant implications for understanding the role of these artifacts in Upper Palaeolithic societies, and the evolution of symbolic behavior and social organization more generally. For this special issue on "The Role of Art in Prehistoric Societies," I present a case study of Early Aurignacian beads in ivory and soapstone, and related production debris, from four sites (Abri Castanet, Abri de la Souquette, Grotte des Hyènes at Brassempouy, Grotte d'Isturitz) in the Aquitaine region of France. The data from the case study are used to evaluate three hypothetical models of production and exchange in the given regional context, and are evaluated in terms of the current, common criteria for the recognition of craft specialization in the archaeological record. Based on these criteria, these artifacts could reasonably be considered the products of specialist producers. I argue that the data presented here indicates two possibilities in the interpretation of prehistoric production-organization: either the presence of craft specialization in the Early Upper Palaeolithic can be accepted, or the criteria for recognizing specialization in the archaeological record should be revised. In either case, there is a demonstrated need for the refinement of models and vocabularies related to production organization in small-scale societies that better reflect the complex patterns apparent in the ethnographic and archaeological records. In addressing these issues, it is necessary to reconsider many basic assumptions about production, wealth, and exchange in Palaeolithic contexts, the perceived limitations of the archaeological record, and thenature and the antiquity of what is considered "complex" social organization. This case study and the arguments that follow are not intended to be a definitive statement on craft specialization and production organization in the Upper Palaeolithic. They are presented as an example of the kind of data-driven modeling of production and exchange in the Early Upper Palaeolithic that can serve as a concrete basis for the reconsideration of production and exchange in these contexts. [ABSTRACT FROM AUTHOR]

The production of waste from the mining-metallurgical sector is one of the factors of environmental contamination and exploring ways to reuse this waste have attracted considerable research attention. This study proposes the use of residues generated from the manufacturing processes of ferromanganese alloy and soapstone powder for the production of red ceramic. Ceramic bricks were prepared with clay and sludge to investigate the effect of a number of variables, including the replacement of clay with sludge (5% and 10%), compaction pressure (14 and 28 MPa), and firing temperature (850 °C and 1000 °C) on the linear shrinkage, water absorption, firing specific weight, and compressive strength of the bricks. Also tests were carried out with replacement of part of the clay mass by sludge and steatite in the same brick. The best condition for ceramic production was found to be a firing temperature of 1000 °C and compaction pressure of 28 MPa with 5% of clay replaced by sludge. The best results were obtained for bricks with clay replaced by both sludge and steatite, which prompted the formation of the new crystalline phases, spinel and enstatite. After analysis, the brick residue was classified as Non Hazardous and Not Inert. The analyzed parameters were within the established limits for technological applications. [ABSTRACT FROM AUTHOR]

The Jiroft valley, situated on banks of the Halil Rud developed as an important agricultural and trading center during the Early Bronze Age. Known for its famous steatite sculptures and clay pottery, the first settlement in Konar Sandal collapsed around 3rd millennium BCE. A second shorter, but major phase of occupation in the settlement occurred towards the end of 2nd millennium BCE. A 250-cm long peat sequence near the archaeological complex at Konar Sandal was investigated to reconstruct the human-environment history using palynological, sedimentological and geochemical data. With a basal age of 4 ka, the core traces the hydroclimatic changes and human activities that started just after large scale abandonment of Konar Sandal and extends from the late Bronze Age to the Mongol invasion. The results show that Jiroft had an arid dry climate dominated by the Saharo-Sindian open pseudo-savanna vegetation. However, due to human clearance and intensified agro-sylvo-pastoral activities, and climatic factors, the land-cover shifted from open xeric scrublands to a more open degraded landscape. The principal human occupation was cereal cultivation and herding. However, it is likely that during the more arid periods, communities retreated and abandoned agriculture, facilitating successional processes. Such droughts occurred around 4.0–3.8 ka and 3.4–2.8 ka and are related to the Siberian Anticyclonic system. Declining Artemisia and shrubs indicate milder climates ca. 3.8–3.4 ka and 2.8–0.6 ka. The latter period that started with the rule of the Persian empires (550–650 BCE), and continued through the Islamic era, coincides with intensive human activities, and the highest degradation of vegetation. [ABSTRACT FROM AUTHOR]

This article investigates the daily practices and social processes of indigenous identity negotiation in the Santa Barbara Channel region through an analysis of soapstone ollas, bowls, and comales. After assessing the source of the raw material and using a typological classification based upon form and function, I discuss the ways in which soapstone cooking wares were used diachronically and across the colonial landscape. These finds show a reorganization of the soapstone industry inside the mission space: soapstone was acquired from new sources, an emphasis was placed on the production of bowls and comales, and more soapstone vessels show evidence of remodification. However, the continued use of traditional soapstone ollas in historically occupied Chumash villages outside the mission indicates persistent practices that linked indigenous peoples to a deep ancestral past. I argue that these changes and continuities illuminate a range of identities that existed between the cultural spaces previously described as “native” and “Spanish.” This study illustrates that indigenous peoples negotiated, redeployed, and expressed their identities in new ways that allowed them to adapt and persist under colonialism. [ABSTRACT FROM AUTHOR]

Purpose High wear resistance of denture teeth preserves good occlusal relationship and sufficient parafunctional stability. This in-vitro investigation aimed to determine and compare the wear performance of different artificial denture teeth. Methods Denture teeth of fifteen commercial products ( n = 8/group) were loaded in a pin-on-block design using steatite antagonists (d = 3 mm). Cyclic loading (50 N) was applied for 120,000 loadings ( f = 1.2 Hz) with simultaneous thermal cycling (distilled water, 5 °C/55 °C, 2 min/cycle). A loading cycle consisted of a vertical 1 mm impact and a subsequent lateral 1 mm sliding movement. Worn areas were digitalized (3-D-laser-scanning-microscope). Maximum and mean wear depth and surface roughness were determined and statistically compared (one-way Anova, Tukey-HSD test, α = 0.05). Worn surfaces and cut specimens were investigated with scanning electron microscopy (SEM). Results Maximum wear varied between 475.1 μm and 1232.2 μm. Mean wear was between 241.1 μm and 753.6 μm with significant differences ( p < 0.001) between individual materials. Mean and maximum wear showed a significant correlation (Pearson’s correlation coefficient: 0.942). Surface roughness increased between unworn to worn surface by 1.2 μm (Ra, p = 0.387) and by 41.7 μm (Rz, p = 0.000). All materials provided round or drop-shaped wear traces. Superficial analysis showed no cracks, chipping or fractures in the worn areas. Detailed evaluation of cut specimens with SEM exposed cracks on the bottom of the wear traces. Conclusions Denture teeth showed significantly different in-vitro wear performance and increased roughness in the wear trace. Differences may be attributed to the composition of the materials, regarding both filler and polymer structure. The selection of teeth might contribute to enhanced in-vivo performance of the denture. [ABSTRACT FROM AUTHOR]

Currently, the term “soapstone” often refers to both talc-bearing ultramafic metamorphic rocks and other rocks having a wide range of variation in mineral composition. As a result, the name provides little information on the major mineral constituents in the rock. This proposal for the classification and nomenclature of soapstones is based on the absolute and relative modal mineral compositions. It does not consider textural attributes. According to the International Union of Geological Sciences, Subcommission on the Systematic of Metamorphic Rocks (IUGS-SCMR), rock names should be understood uniquely and without ambiguity. Therefore, we recommend: (1) soapstone has to contain 35-75% talc, (2) soapstone cannot contain more than 35% hard silicates. Further division is made based on the ratios of oxide, chlorite, and carbonate. Finally, the name of the additional hard silicate is considered as a prefix, if its content exceeds 5%. [ABSTRACT FROM AUTHOR]

Objective The aim of this laboratory study was to analyze the influence of titanium dioxide (TiO 2 ) content and antagonistic material on the wear of polyetherketoneketones (PEKKs). Methods Twenty-four disk-shaped specimens of two PEKK materials containing either 10 wt% or 20 wt% TiO 2 particles (P10 and P20) were dynamically loaded in a chewing simulator with 49 N and additional thermal cycling (5–55 °C). Subgroups of 8 specimens each were loaded with spherical antagonists made from either steatite ceramic (St), zirconia (Zr), or the same PEKK material (P10 or P20). After 120,000, 240,000, 480,000, 840,000, and 1,200,000 loading cycles the vertical substance loss and the volume loss of the loaded specimens were evaluated using a laser scanner. Data were checked considering the normal distribution (Shapiro–Wilk test) and were inspected for significant differences by means of single factor variance analyses and post hoc pair comparison (Games-Howell test). Results After 1,200,000 chewing cycles, statistical analyses revealed a significant influence of the antagonistic material. A significant difference was also found between the tested PEKKs if Zr was used as the antagonist. The volume loss ranged from between 0.073 mm 3 (P20-P20) and 0.228 mm 3 (P10-St), and the vertical substance loss ranged between 73.71 μm (P20-P20) and 115.268 μm (P10-Zr). Significance The inclusion of TiO 2 particles influences the wear behavior of PEKK materials. [ABSTRACT FROM AUTHOR]

In this work, a numerical model of the heat transfer through composite wood stove walls has been used to study the effect of material configurations on the heat storage and the heat release profile to the room, to arrive at improved thermal comfort performance. Cast iron and soapstone have been compared, showing that soapstone is a good material from a thermal comfort point of view, while cast iron (for the typical stove weights of today) exhibits a comparably higher peak and faster heat release. Applying a Phase Change Material (PCM) for such a cast iron stove changes this picture. It makes it possible to reduce peak heat release and achieve a more stable as well as an extended heat release period. 53% reduction in peak and 43% reduction in average heat release was demonstrated during the combustion cycle using Erythritol as PCM. However, the selection and use of a PCM must be optimized. Its capacity should be utilized to a maximum extent without overheating the material as it will cause irreversible damage to most PCM. [ABSTRACT FROM AUTHOR]

The article focuses on Appalanchian Blades represented throughout Tennessee River Valley which are biface blades with squared stems and mention association of blades with steatite. Topics discussed include finding of the Appalachian quartzite biface blades in field along Mulberry Creek in Caldwell County in North Carolina, Appalancian type made of lithic material such as rhyolite and quartz and blades stored in cache context.

This study aimed to evaluate the action of organic acids produced by the fungal population associated with the biodeterioration process of the Twelve Prophets of Aleijadinho, a set of soapstone sculptures in Congonhas, state of Minas Gerais, Brazil. For this, samples of fungi were obtained from the surface of each of the 12 outdoor stone sculptures that comprise the set of Prophets. The identification of the colonizing filamentous fungi was performed by classical microbiology and molecular methods. Some species of filamentous fungi-dependent cultivation were detected, and the presence of species Aspergillus versicolor, Curvularia lunata, Epicoccum nigrum, Penicillium citrinum and Pseudocercospora norchiensis indicated a connection with the excretion of organic acids. The acids produced by each of these fungal species were analysed quantitatively by chromatographic methods, revealing potential biodeterioration by the action of acidic metabolites excreted in the stone. Significance and Impact of the Study Minas Gerais, Brazil, is vulnerable to the activities of mineral extraction industries, posing an imminent risk to United Nations Educational, Scientific and Cultural Organization ( UNESCO) recognized cities, e.g. Congonhas. Many of these municipalities hold many soapstone religious sculptures and historical monuments. Consequently, soapstone is susceptible to filamentous fungi attack causing irreversible biodeterioration. Despite the concern related to nondestructive sampling of 18th century sculptures, in this study, we have discussed the factors that lead to biodeterioration of soapstone due to organic acid excretion by the fungi that damage the stone, thereby providing an insight in conserving and preserving the soapstone monuments. [ABSTRACT FROM AUTHOR]

The focus of the study was on providing insights into interconnections between sintering and development of the crystalline microstructure, and consequently variations in dielectric behavior of four steatites fabricated from a low-cost raw material, i.e. talc. The changes, induced by the alternations of the binders (bentonite, kaolin clay) and fluxing agents (BaCO 3 , feldspar), were monitored in the temperature range 1000° to 1250 °C in which complete densification and re-crystallization of the investigated structures were accomplished. The critical points in the synthesis of steatite materials were assessed by instrumental analyses. Crystallinity changes and mineral phase transition during sintering were monitored by X-ray diffraction technique. Microstructural visualization of the samples and the spatial arrangements of individual chemical elements were achieved via scanning electron microscopy accompanied with EDS mapping. The thermal stability was observed on the green mixtures using differential thermal and thermo gravimetric analyses. Electrical measurements recorded variations of the dielectric constant (ε r ) and loss tangent (tan δ) as a function of the sintering temperature. The investigation highlighted critical design points, as well as the optimal combinations of the raw materials for production of the steatite ceramics for advanced electrical engineering applications. [ABSTRACT FROM AUTHOR]

This study evaluated the life cycle of a prototype unit for production of handcrafts in soapstone, located in Mata dos Palmitos community in Minas Gerais, through a mass balance methodology between the inputs and outputs of raw material, water and system energy, based on ABNT NBR ISO 14040:2009 Gestão ambiental - Avaliação do ciclo de vida - Princípios e estrutura. The project proved to be sustainable as its main goal, which is to improve the quality of life of local artisans by suppressing mineral dust through the implementation of clean technologies, and improve environmental quality and reduce raw water demand through reuse. [ABSTRACT FROM AUTHOR]

A cache of 12 soapstone vessels from the Claiborne site in Mississippi was recently repatriated to the state after being excavated in 1968 and removed to Ohio. As a locus of Poverty Point affiliation, Claiborne was positioned along a Gulf Coast route for the influx of soapstone into the lower Mississippi valley from quarries in the southern Appalachians, hundreds of kilometers to the east. Although residents of Claiborne were likely to have been active traders during the heyday of Poverty Point exchange, ca. 3600–3400 cal BP, new AMS assays on carbon deposits from seven of the soapstone vessels show that the cache was emplaced ~200 years later, during or shortly before the abandonment of Poverty Point. Reported here are the results of AMS assays, observations on vessel form and function, and preliminary inferences about the significance of the cache in the context of environmental and cultural change after 3200 cal BP. [ABSTRACT FROM PUBLISHER]

Objectives This study evaluated the wear performance and wear mechanisms of four dental glass-ceramics, based on the microstructure and mechanical properties in the progressive wear process. Methods Bar (N = 40, n = 10) and disk (N = 32, n = 8) specimens were prepared from (A) lithium disilicate glass-ceramic (LD), (B) leucite reinforced glass-ceramic (LEU), (C) feldspathic glass-ceramic (FEL), and (D) fluorapatite glass-ceramic (FLU). The bar specimens were tested for three-point flexural strength, hardness, fracture toughness and elastic modulus. The disk specimens paired with steatite antagonists were tested in a pin-on-disk tribometer with 10 N up to 1000,000 wear cycles. The wear analysis of glass-ceramics was performed using a 3D profilometer after every 200,000 wear cycles. Wear loss of steatite antagonists was calculated by measuring the weight and density using sensitive balance and Archimedes’ method. Wear morphologies and microstructures were analyzed by scanning electron microscopy (SEM). The crystalline phase compositions were determined using X-ray diffraction (XRD). One-way analysis of variance (ANOVA) was used to analyze the data. Multiple pair-wise comparison of means was performed by Tukey's post-hoc test. Results LD showed the highest fracture toughness, flexural strength, elastic modulus and crystallinity, followed by LEU and FEL, and FLU showed the lowest. However, the hardness of LD was lower than all the other three types of ceramics. For steatite antagonists, LD produced the least wear loss of antagonist, followed by LEU and FEL, and FLU had the most wear loss. For glass-ceramic materials, LD exhibited similar wear loss as LEU, but more than FLU and FEL did. Moreover, fracture occurred on the wear surface of FLU. Conclusions In the progressive wear process, veneering porcelains showed better wear resistance but fluorapatite veneering porcelains appeared fracture surface. Monolithic lithium disilicate glass-ceramics with higher mechanical properties showed more wear loss, however, they did not fracture and produced less wear loss of antagonists. [ABSTRACT FROM AUTHOR]

An experimental investigation was made on flow properties and compressive strength of self-compacting concrete (SCC) with ultrafine natural steatite powder (UFNSP) as replacement to cement. The tests were conducted on specimens with 5%, 10%, 15%, 20%, and 25% of replacement of UFNSP to the weight of cement and compared to the control specimens. The flow properties of all specimens were tested and checked for their limit with the existing guidelines. The compressive strength test was done on all specimens for strength of 7 days, 14 days, 28 days, and 56 days. The hardened samples were tested for their microstructural behavior and the elements Mg, Ca, and Si were mapped. Through mapping, the formations of M-S-H along with C-S-H are observed. The results show that the addition of UFNSP influences the flow property, by reducing the flow, and increases the compressive strength till 20% replacement. Further the addition of UFNSP increases the denseness of microstructure of the specimens thus resulting in the strength increment. [ABSTRACT FROM AUTHOR]

The work aimed with the effect of preceramic mixtures containing natural talc (Tc) or acid-treated talc (Tc-ac) supplemented by montmorillonite (Mt) or kaolinite (Ka), and the flux Na2 CO3 on the mineral phase composition, porosity and pore size distribution in the steatite ceramics prepared using solid state sintering at 1300°C. The samples were analyzed using X-ray diffraction and porometry techniques and scanning electron microscopy. Application of Mt or Ka in preceramic mixtures with provided comparable results. The acidification of talc using hydrochloric acid resulted in partial release of Mg2+ from the structure. The ratio of SiO2:MgO in Tc was 35:65 (wt%) and 70:30 (wt%) in Tc-ac. Tc, clay minerals, and flux Na2 CO3 in the MgO-Al2O3-SiO2-Na2O glass system resulted to the separation of forsterite and protoenstatite, while Tc-ac provided crystallization of protoenstatite at the expense of clinoenstatite in highly porous ceramics. The preceramic mixtures were precursors of bimodal pore size distribution at prepared steatite ceramics. [ABSTRACT FROM AUTHOR]

This paper covers the dynamics of Soapstone Craft of Dhakotha. Broadly this paper can be divided into two parts, i.e., crafts study part and product design intervention part. The crafts study part includes- research methods, craft introduction, crafts location, craft history, available raw materials, craftsmen and existing skill sets, tools under use, involved craftsmanship processes, existing product ranges etc. On the basis of understandings developed during crafts study, this researcher had explored different market specific and end-user focused product design possibilities. The product design intervention part includes different product design interventions and collections developed by researcher with a holistic approach. There are two different soapstone clusters, with different skill sets, i.e., Soapstone carving cluster and Soapstone ପତ୍ଥର କୁଣ୍ଡ or Patthar Kundo cluster; are practicing in same geographical area, so studying and exploring interventions in joint mode was an interesting experience for this researcher. This craft study cum design intervention initiative was conducted during 2010-2011 by this author. [ABSTRACT FROM AUTHOR]

Soapstone industry utilizes different types of soapstone mainly as a construction material for fireplaces. In this application soapstone has to meet different temperature requirements in different parts of fireplaces. Mineralogical and structural information is needed for placing an appropriate type of soapstone in an appropriate position in the fireplace construction. This allows employment of higher temperatures resulting in more particulate-free combustion, which makes it possible for soapstone industry to develop more efficient and environmentally friendly fireplaces. Of many soapstone types, which differ from each other in their chemical composition and thermal properties, carbonate soapstone and its microstructural variations were investigated in this study. A new method was developed to measure thermal shock resistant of natural stones. By exposing carbonate soapstone samples of different textural types to rapid temperature changes, it was possible to determine the parameters that affect the capacity of the rock to resist thermal shock. The results indicate that the type of microtexture is an important factor in controlling the thermal shock resistance of carbonate soapstone. The soapstone samples with a high thermal shock resistance show deformation textures, such as crenulation cleavage and S/C mylonite. A strong negative correlation was observed between the thermal shock resistance and length of cleavage domains in foliated rocks. Also a slight elevation in the iron concentration of talc and magnesite was discovered to improve the thermal shock resistance of carbonate soapstone. Attention should especially be paid to the length and planarity of cleavage domains of spaced foliation. [ABSTRACT FROM AUTHOR]