Introductory Chapter: Overview of the Properties and Applications of Noble and Precious Metals

The noble and precious metals correspond to a selection of the transition-metal group of the periodic table (see Figure 1), including copper (Cu), silver (Ag), gold (Au), platinum (Pt), palladium (Pd), iridium (Ir), osmium (Os), ruthenium (Ru), rhodium (Rh), and rhenium (Re). Pt also gives its name to a distinct subset of these elements, known as the platinum group, which include Ru, Rh, Pd, Os, Ir, and of course Pt. Additionally, Ru, Rh, Re, Os, and Ir are considered refractory metals—defined by melting points exceeding about 2000°C— along with several more abundant and commonly used transition metals, such as titanium (Ti), chromium (Cr), molybdenum (Mo), and tungsten (W). The noble and precious metals generally crystallize in the face-centered cubic (fcc) structure except for Ru, Re, and Os, which have the hexagonal close-packed (hcp) structure. The use of Cu, Ag, Au, and Pt in jewelry and coinage has been known throughout human history. The chapters presented in this book deal with other applications of some of these metals along with their fundamental properties.