Beryllium is an extraordinary metal with an unusual combination of physical and mechanical properties. It has low density, high stiffness, and excellent dimensional stability. It is also transparent to x-rays and can be machined to extremely close tolerances. This chapter discusses the properties, compositions, and processing characteristics of beryllium and its alloys. It provides information on powder production and consolidation, commercial designations and grades, wrought products, and forming processes. It also discusses the issue of corrosion, the use of protective treatments and coatings, and health and safety concerns.