An amalgam tattoo or amalgam pigmentation is the most frequently seen colour change with exogenous origin in the oral cavity. It occurs due to traumatic application of dental amalgam into mucosal tissue. Accordingly, the even macula typically adjoins the amalgam restauration (or where one used to be) and is most often located on the gingiva and alveolar mucosa. Depending on whether the metal is deposited in solid fragments or in numerous fine granules, the size and form varies between irregular blue to dark grey coloured maculas, diffuse dispersed pigmentation or a combination of both. A radiograph represents (larger) metallic particles and helps to confirm the diagnosis. Except for cosmetic reasons, a treatment is not induced.