Germanium (Lat. Germanium) is a metalloid whose physical and chemical properties are very close to those of silicon. It is a brittle, non-toxic, grey-white element with poor electrical conductivity. Germanium has a melting point of 937.4°C and a boiling point of 2830°C. Due to its relatively high market price, germanium (chemical symbol Ge) is not widely used in everyday equipment. Germanium is used in the manufacture of motion sensors, power rectifiers, various LEDs, and night vision devices. It is also sometimes used in jewellery production.
Germanium is also used in some transistors and other semiconductor devices. While silicon is a more common manufacturing material in this field, germanium is more often used as a more efficient choice in the field of high frequency transistors. Germanium dioxide is used in the manufacture of fibre optics; in fibre optics, germanium helps to improve the quality of light transmission and reduce the loss of fibre efficiency. Germanium-based solar cells are used in aerospace and other specialised applications due to their high efficiency.
Source:
https://www.britannica.com/science/germanium
https://en.wikipedia.org/wiki/Germanium