Germanium is 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.
Three reasons Germanium stands out
- 1
Used in early transistors and fiber optics.
- 2
Mendeleev predicted its existence before it was discovered, accurately forecasting its properties and calling it "eka-silicon."
- 3
It is used in infrared optics and night-vision equipment because it is transparent to infrared light.
The semiconductor before silicon took over
Germanium enabled the first generation of transistors and remains useful where its optical and electronic behavior outperforms silicon. Infrared light passes through germanium, making it valuable in thermal cameras and lenses. It is usually recovered as a by-product rather than mined from dedicated germanium ore.