Aluminium amalgam Aluminium amalgam Aluminium can form an amalgam in solution with mercury. Aluminium amalgam may be prepared by either grinding aluminium pellets or wire in mercury, or by allowing aluminium wire to react with a solution of mercury(II) chloride in water. This amalgam is used as a chemical reagent to reduce compounds, such as the reduction of imines to amines. The aluminium is the ultimate electron donor, and the mercury serves to mediate the electron transfer. The reaction itself and the waste from it contain mercury, so special safety precautions and disposal methods are needed. As an environmentally friendlier alternative, hydrides
Amalgam tattoo from pencil leads), and is sometimes termed a "graphite tattoo", although this is less common than tattooing with amalgam. The diagnosis is clinical. Amalgam tattoo can be distinguished from other causes of localized oral pigmentation because it does not change significantly in size or color, although it may appear to slowly enlarge for several months after the initial implantation of the metal particles. Some amalgam tattoos appear radio-opaque on radiographs (i.e. they show up on x-rays), although in many cases amalgam tattoos have no radiographic features since the responsible particle(s) of amalgam are very small even though clinically the area