Annealing (metallurgy) brass can be cooled slowly in air, or quickly by quenching in water, unlike ferrous metals, such as steel, which must be cooled slowly to anneal. In this fashion, the metal is softened and prepared for further work—such as shaping, stamping, or forming. Annealing occurs by the diffusion of atoms within a solid material, so that the material progresses towards its equilibrium state. Heat increases the rate of diffusion by providing the energy needed to break bonds. The movement of atoms has the effect of redistributing and eradicating the dislocations in metals and (to a lesser extent) in ceramics. This
Glass marimba of mallets are used for different effects. The tuning system of a glass marimba can be whatever is desired. Glass marimbas are utilised by the Brazilian percussion ensemble, Uakti. Glass marimba can be constructed in a variety of ways. How one resonates the keys governs the construction method and design. Resonation can be accomplished using a single resonator which all the keys resonate into, such as an open top box, or individual resonators for each key which can be a tube, box, or sphere. Single box resonators can be constructed from wood, glass, or metal among a variety of materials.