Science lifts the veil on ancient bracelet Cutting-edge computer analysis of the earliest obsidian bracelet ever discovered—dated to 7 500 BC and found in 1995 at the Asıklı Höyük site in Turkey—have revealed the astounding expertise of prehistoric Anatolia craftsmen, who were able to create perfectly regular objects. The finish of the surface, in particular, points to the use of complex polishing techniques to obtain nanometer-scale surface quality. Journal of Archaeological Science August 2011 This damaged manuscript was written with iron gall ink. Widely used from the Middle Ages to the early 20th century, this ink causes severe alteration of the paper. Manuscript oxidation becomes clearer Paper deterioration in ancient manuscripts is essentially caused by cellulose oxidation, speeded up by the Fe²+ ions in the iron gall inks they contain. These black inks, made up of iron salts, gum arabic and aqueous extracts of oak-galls, were widely used in the West from the Middle Ages to the twentieth century. Reducing the amount of oxygen in the ambient air would help to improve the preservation of these written treasures of human heritage. Analytical Chemistry March 2011 Micro-samples were collected from this painting by Murillo, The Heavenly and Earthly Trinities (The Pedroso Murillo). The blue pigments that betrayed Murillo Fortress under threat from flowers Why does the color blue often turn grey in paintings of the sixteenth- The French-Serbian team that examined the deterioration of the walls eighteenth centuries, especially in those by Murillo? Since the seventeenth of the Belgrade Fortress are categorical: the damage is caused by century it has been known that smalt—a blue pigment used for the fertilizers used by gardeners on flowerbeds. High concentrations centuries—is unstable, but the reason for this was not known. A team has of potassium contribute to the formation of a black crust that stains now found it: potassium ions tend to migrate out of the grains of pigment, the ramparts, which date from the Middle Ages. The best solution leading to a change in the coordination of the cobalt ion, which in turn to preserve this area, where Serbs love to walk and relax, would causes the loss of the blue color. therefore be to avoid excessive use of fertilizers. Analytical Chemistry May 2011 Journal of Cultural Heritage October 2011 Oldest pigment workshop reveals its secrets ------------------------------------------------------------------------------------------------------------------------------------------------- The remains of a 100,000-year-old pigment workshop, discovered in 2008 in the Blombos Cave in South Africa, have helped a team of archeologists reconstruct the production techniques used by these early craftsmen. By crushing minerals such as haematite and goethite to a powder, they made yellow and red pigments, using bone marrow as a binder. Various hypotheses about the potential uses of these pigments have been put forward by researchers, ranging from coloring and protecting materials (skins, body paints) to treating ailments, or producing abstract and figurative art. The complexity of the techniques used in this workshop, the earliest ever discovered, suggests that the craftsmen had cognitive abilities that enabled them to plan ahead and carry out complex tasks, such as combining raw materials of different kinds and origins. Science October 2011 27 2011 A year at CNRS
ra2011
To see the actual publication please follow the link above