Mineralized artifact

Fed by melting snow from the Himalayas, the Indus River and its tributaries sustain life in central Pakistan. South Asia s first urbanized civilization developed in the Indus River valley in the period 2600-1900 B.c. An archaeologist posed the question, With whom were the residents of the Indus Civilization interacting when they acquired rock and mineral resources " Many archaeological rock and mineral artifacts were studied, but we will focus on silver ornaments found at Allahdino and Mohenjo-daro (Figure 20-19). 

Deteriora.tlon. Apart from physical damage that can result from carelessness, abuse, and vandaUsm, the main problem with metal objects Hes in thek vulnerabihty to corrosion (see Corrosion and corrosion control) (127,128). The degree of corrosion depends on the nature and age of the object. Corrosion can range from a light tarnish, which may be aesthetically disfiguring on a poHshed silver or brass artifact, to total mineralization, a condition not uncommon for archaeological material. 

Rubidium-87 emits beta-particles and decomposes to strontium. The age of some rocks and minerals can be measured by the determination of the ratio of the mbidium isotope to the strontium isotope (see Radioisotopes). The technique has also been studied in dating human artifacts. Rubidium has also been used in photoelectric cells. Rubidium compounds act as catalysts in some organic reactions, although the use is mainly restricted to that of a cocatalyst. 

Sandoli RL, WC Ghiorse, EL Madsen (1996) Regulation of microbial phenanthrene mineralization in sediment samples by sorbent-sorbate contact time, inocula and gamma irradiation-induced sterilization artifacts. Environ Toxicol Chem 15 1901-1907. 

Fibrous mat type filters include the frequently used paper (cellulose) fiber filter, for example, the Whatman paper filter, and glass fiber filters. A common fibrous mat filter used for sample collection and air cleaning is known as the HEPA filter (/zigh efficiency particulate air filter) and is made of a combination of cellulose and mineral fibers. A widely used type of fibrous mat filter is the high-volume filter, commonly referred to as Hi-Vol, shown in Fig. 11.56. A modification of the Hi-Vol filter to increase the total air flow allows the collection of sufficient particulate matter in relatively short time periods (e.g., 2 h) to cany out chemical analysis this is important for studies of the diurnal variation of various chemical components of the aerosol as well as for minimizing sampling artifacts (Fitz el ai, 1983). 

Archaeological artifacts are considered to be objects that have been buried for very long periods of time—sometimes many centuries or even millenaries. After such long periods, they are deeply modified, consisting of mostly a mixture of metallic remnants and mineral products, which sometimes hinders their identification (Fig. 5.2). 

One important application of electrolytic treatment is the removal of harmful anions, such as chloride and sulphide, from the mineralized archaeological artifacts. The negative polarization of the system repels the negatively charged species out of the cathode. The process is often accompanied by the formation of either gas or soluble species in the electrolyte. This kind of treatment was carried out to increase the rate of extraction of chlorides from iron (see Fig. 6.1) [295], copper [296], and aluminium [297] mineralized objects. 

Degrigny C (1995) Stabilisation de moteurs d avion immerges. Stud Conserv 40 10-18. Organ RM (1967) The reclamation of the wholly mineralized silver in the Ur lyre. In Application of Science to Examination of Works of Art, Museum of Fine Arts, Boston, 126-144. Degrigny C, Le GaU R (1999) Conservation of ancient lead artifacts corroded in organic acid environments electrolytic stabilization/consolidation. Stud Conserv 44 157-169. 

In analyzing the fibers at a microscopic level, the general fiber classes were identified (hair or bast). Furthermore, adherence of particles to the fibers, be they mineral colorant or soil was determined and when possible identified with the help of the particle atlas (38). The previously created control mounts were used as comparative materials to the unknown mineral or pigment deposits that were observed in foe artifact samples. 

Using forensic photography as a precursor to any sample acquisition forms the foundation of the protocol, and allows purposive sampling. EDS should be performed to establish which elements to expect before attempting any quantitative elemental analysis such as ICP-OES/MS. Before working with actual artifacts, a set of replicated materials must be used and a successful trial run using the planned methods of analysis whether ICP-OES/MS, GC-MS or any others, must be achieved, so the methods of preparation can be adjusted properly. To facilitate this, appropriate materials must be replicated, which might mean that plants or minerals must be collected, and dyed or painted comparative standards must be created, so the unknown can be compared to the known. For many of the Old World dye plants these standards already exist. However, for North American dye plants comparative collections are in the early phases and subsequent analysis of colorant constituents have not yet been conducted (68,69). 

Soils can have characteristics due to human activity (anthropogenic soils). The forensic examination of soil is therefore not only concerned with the analysis of naturally occurring rocks, minerals, plant, and animal matter it also includes the detection of such manufactured materials as ions from synthetic fertilizers and from different environments (e.g., nitrate, phosphate, sulfate) and environmental artifacts (e.g., lead or objects such as glass, paint chips, asphalt, brick fragments, and cinders). Each of these materials can represent distinct soil characteristics. When unique particles are found in soil evidence, more precise and rapid discrimination can be achieved even if the amount of evidence recovered is microscopic (Sugita and Marumo 2004). For this reason, microscopy is often considered the most useful technique for the detection of such characteristic particles. 

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