Bandelier National Monument (BNM) was created to protect an extraordinary inventory of archaeological resources carved in the Tshirege Member of the Bandelier Tuff. These include more than one thousand excavated chambers, called cavates, used for dwelling, storage, and textile production. The glass-rich tuffs at the base of the Tshirege Member are poorly consolidated and susceptible to erosion by wind, rain, and mechanical abrasion, with resultant loss of cultural material. However, rock surfaces develop protective weathering rinds that are resistant to erosion. Using optical microscopy, SEM-EDS, XRD, and electron microprobe analysis, we determined that this rind consists of clay and silt sediments colonized by lichens and other surface biota, accompanied by the precipitation of secondary minerals in the near-surface pore space. Scoping experiments focused on glass-organic acid interactions indicate that oxalic acid excreted by microbial crust constituents catalyzes biogeochemical reactions that lead to the preferential dissolution of Si, Al, and Fe components of the volcanic glass; these cations become available for precipitation of opal, and smectite and sepiolite clays. Enzyme assays that quantify biological activity at outcrop surfaces indicate that microbial populations initially thrive as they derive nutrients from the dissolution reactions of the glass, but activity starts to decline as precipitation of secondary minerals limits access to new sources of nutrients, so that alteration processes are self-limiting. As case hardening progresses, imbibition rates at the surface decrease, and the erosion resistance of the altered surfaces is substantially improved. This article presents summary results of research conducted over a period of five years to characterize the roles of lichens and other microflora in rind formation, and the resulting contributions to tuff stability. The interaction of lichens and other microflora with rock surfaces in archaeological sites and monuments is usually explored in terms of biodeterioration and consequent damage. However, this study shows that, under some circumstances, lichens and microflora provide a level of erosion protection to relatively porous and unconsolidated rock strata that outweighs their biodeteriorative effects.

Synthetic organic pigments (SOPS) find wide use in modern and contemporary works of art. These laboratory-made pigments are used in many fields, including industrial and architectural paints, printing inks, plastics, textiles, and artists’ materials. They have been examined by a variety of techniques including spectroscopic methods such as Fourier transform infrared spectroscopy (FTIR), Raman, and X-ray powder diffraction (XRD) as well as chromatographic or mass spectrometric techniques such as pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and laser desorption ionization mass spectrometry (LDI-MS). Often, a combination of techniques has been used to examine these pigments. Previously, we used a combination of Raman spectroscopy and LDI-MS to characterize commercially available SOPS. However, many pigments, termed “historical” are no longer manufactured, and therefore, may not have been characterized. This paper describes the synthesis of members of several classes of SOPS and their characterization.

Given the lack of satisfying treatments for consolidating marble affected by thermally induced grain detachment (the so-called "sugaring"), the use of aqueous solutions of diammonium hydrogen phosphate (DAP) has recently been proposed. The idea is to form a new binding mineral (hydroxyapatite, HAP) as the reaction product between the DAP solution and the calcitic substrate. In this study, we investigated the effects of adding small quantities of ethanol (EtOH) to the DAP solution, with the aim of favoring HAP formation. The results of the study indicate that, when a 0.1 M DAP and 0.1 mM CaCl2 solution in 10 vol% EtOH is used, complete coverage of marble surface with a crack-free coating with reduced porosity is achieved (whereas no coating is formed without EtOH addition). This is thought to be a consequence of the weakening of hydration shells of phosphate ions in the DAP solution, thanks to the presence of ethanol molecules. When used to restore mechanical properties of weathered marble, the treatment with 10 vol% EtOH was found to significantly improve the dynamic elastic modulus after a single application and to completely restore it after a second application.

Off-white water pots have had sustained traditional acceptance for a long period of time in Jodhpur compared to red colored water pots imported from the neighboring Gujarat state. Both types of pots hold 20 liters of potable water. The fluorescence spectroscopy reveals dominance of silica, alumina and iron oxide in red pots from Gujarat whereas off-white pots from Rajasthan also have a slight excess of CaO and MgO. Fourier transform infrared spectroscopy reveals a firing temperature of 800 °C for off-white pots, which is comparatively less than that for red pots. A lower amount of Fe2O3 and higher MgO in off-white compared to red water pots is responsible for the color differentiation. Off-white pots show a better degree of cooling compared to red pots. Better resistance to load was observed in off-white pots compared to red pots. This study may imply influence of hidden techno-functional aspects towards sustainability of off-white pots in Jodhpur, Rajasthan.

Ancient Chinese bronzes are precious cultural relics. Their surfaces are often severely damaged by dynamic changes in the external environment, both before and after they are unearthed. Therefore, scientific research has been required to preserve these treasures. In recent years, along with the development of modern science and technology, innovative instrumental analytical techniques have become indispensable tools to study corrosion phenomena as well as to evaluate post-excavation conservation techniques. In this paper, we present an overview of bronze corrosion processes in various environments, including analysis of the types of corrosion, mechanisms of formation and factors that influence bronze corrosion products. In addition, we compare the characteristics of corrosion products that have formed on archaeological sites, in tombs, and in museums. Lastly, we introduce some novel techniques for bronze protection, and we propose the focus for future research. Our expectation is that this review will provide a scientific basis for bronze preservation.

A group of traditional pottery workshops in Sichuan Province, China, produce a unique coal-clay composite ceramic that is fired using a similarly unique kiln design and two-stage firing procedure not seen in any other ceramic tradition. Here we report on field and laboratory efforts to better understand this unusual ceramic material and technology, the functional advantages as cookware, braziers, and large storage vessels that include high strength and high thermal shock resistance, and the cultural context that supported the creativity and experimentation needed to develop such an innovative technology.