a chemical element with symbol Ge and atomic number 32. It is a lustrous, hard, grayish-white metalloid in the carbon group, chemically similar to its group neighbors tin and silicon. Purified germanium is a semiconductor, with an appearance most similar to elemental silicon. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature. Unlike silicon, it is too reactive to be found naturally on Earth in the free (native) state.

Bulk commercial germanium is sold in ingot bars: This is the broken end of one, showing its internal crystal structure. Germanium is used in light emitting diodes and semiconductors, just like silicon above it.