Composition: Zinc (pure).

Processing: Sand casting.

Etching: cotton impregnated with a diluted solution of HCl (50%) until the macrostructure is revealed.

Radial structure typical of cast pure metals. There are equiaxial grains in the periphery of the specimen and columnar grains in the central region. The amount of reflected light varies from grain to grain depending on the light's angle of incidence and degree of etching, which in turn depends on the crystallographic orientation. It is also possible to observe some polishing lines and lenticular twins. The large columnar grains are undesirable as they make the material brittle.

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