Germanium (Ge) is element number 32 in the periodic table. This white-gray, glossy metalloid is found in nature in the form of compounds. Pure germanium can only be obtained through industrial methods. It has a wide range of applications in science, technology, and medicine. Some of its isotopes are radioactive, but in small quantities, germanium is essential for proper human body functioning.
Two “Fathers” of Germanium
In 1869, Russian scientist Dmitri Ivanovich Mendeleev gave a presentation where he predicted the existence of unknown chemical elements, including germanium, through calculations. He initially called one of them ekasilicon because the predicted element resembled silicon in its properties.
Fifteen years later, in a Saxon mine, a previously unknown mineral, argyrodite, was discovered. Chemist Clemens Winkler studied the find and identified a new element. Winkler considered naming it neptunium, but that name had already been given to another element predicted by Mendeleev. Thus, the element was named germanium, in honor of Winkler’s homeland. Mendeleev not only supported this decision but became good friends with Winkler.
An Elusive Metalloid
Germanium is rarely found in its free state. It exists in trace amounts in the Earth’s crust, found in sulfurous minerals, iron ores, and in compounds with coal, sulfur, and silicon. Despite its rarity, germanium is more abundant than silver, antimony, and bismuth. Studies have shown that germanium is also present in the Sun, meteorites, ocean waters, and even in plants and animals.
Fragile Like Glass, Valuable Like Gold
In chemical reactions, germanium behaves similarly to silicon but is even less metallic in nature. Under normal conditions, it is resistant to water, acids, and alkalis but can dissolve in hot, concentrated acid solutions.
Germanium is almost as fragile as glass, breaking easily, but its price rivals that of gold. It’s one of the few substances that increases in density when it melts. Germanium melts at 938.25°C.
A Valuable Element from… Waste and Dust
Nearly half of the world’s germanium supply is extracted in the U.S., with slightly less coming from China. Production of germanium in the USSR began intensively in 1959. A unique technology was developed at a plant in Orenburg, Russia, to extract germanium from copper smelting waste and coal dust. This allowed the USSR to stop importing germanium and even start exporting it.
Soviet chemists were the first in the world to extract germanium from copper pyrite ores, a pioneering achievement in 20th-century metallurgy.
Dental Crowns and Fiber Optics: Where Germanium is Used
Germanium’s applications are broad, spanning various fields of science and technology:
- Electronics: Germanium is a semiconductor, meaning its electrical resistance changes with temperature. This property was first utilized during World War II in the creation of diodes. In the late 1940s, the first germanium transistor was produced. By the 1970s, silicon became more commonly used in electronics due to its durability and cost-effectiveness.
- Optics: Pure metallic germanium is transparent in the infrared spectrum, making it ideal for lenses, prisms, thermal imagers, microscopes, night vision devices, fiber optic cables, microwaves, and rewritable DVDs.
- Nuclear physics: It is used as a detector for gamma radiation.
- Metallurgy and chemical industry: Germanium acts as a catalyst in certain processes.
- Jewelry making: Germanium is used to create silver alloys of 935 or 960 purity, forming a protective oxide layer on the surface. It also hardens gold and was previously widely used for making gold dental crowns, which have now largely gone out of fashion.
Poison and Healer
As a trace element, germanium is present in the human body, animals, and plants. It is not toxic, except in chloride and hydride compounds (germanium hydride is a potent poison that can depress the circulatory and nervous systems).
However, some studies suggest that certain germanium compounds might be used as treatments for serious diseases. For example, lab rats given small amounts of germanium lived 30% longer than those without it.
In the 1960s, Japanese doctor Kazuhiko Asai found that germanium positively affects the circulatory system. Like hemoglobin, germanium helps distribute oxygen throughout the body, preventing diseases of the liver, heart, and kidneys caused by oxygen deficiency.
Other Beneficial Properties of Germanium:
- Strengthens the immune system by promoting the formation of gamma interferons, which fight infections.
- Helps remove toxins and radiation, improving overall vitality.
- Exhibits anti-cancer properties by preventing metastasis as a natural antioxidant.
- Provides pain relief and promotes wound healing.
- Balances hormones and participates in the production of natural insulin, which helps prevent diabetes.
Why We Lack It and Where to Find It
The daily requirement for germanium is 10 mg, but most people consume only about 1.5 mg. Signs of germanium deficiency include increased bone fragility and a higher risk of cancer. A deficiency can occur due to metabolic disorders or insufficient intake through food.
Foods rich in germanium include:
- Garlic (bulbs and greens)
- Ginseng
- Tomato juice
- Salmon
- Bran
- Seafood and seaweed
- Legumes
The trace element that enhances the beneficial properties of germanium is selenium. Doctors recommend taking them in combined vitamin supplements.