Germanium is a metal or not. Characteristics of the chemical element germanium
(Germanium; from Latin Germania - Germany), Ge - chemical. element of group IV of the periodic system of elements; at. n. 32, at. m. 72.59. Silvery-gray substance with a metallic sheen. In chem. compounds exhibit oxidation states + 2 and +4. Compounds with an oxidation state of +4 are more stable. Natural germanium consists of four stable isotopes with mass numbers 70 (20.55%), 72 (27.37%), 73 (7.67%) and 74 (36.74%) and one radioactive isotope with mass number 76 ( 7.67%) and a half-life of 2,106 years. Many radioactive isotopes have been produced artificially (using various nuclear reactions); highest value has the isotope 71 Ge with a half-life of 11.4 days.
The existence of the holy germanium (under the name “ecasilicon”) was predicted in 1871 by the Russian scientist D.I. Mendeleev. However, only in 1886 The chemist K. Winkler discovered an unknown element in the mineral argyrodite, the properties of which coincided with the properties of “exasilicon.” Start of the prom. Germanium production dates back to the 40s. 20th century, when it was used as a semiconductor material. Germanium content in earth's crust(1-2) 10~4%. Germanium is a trace element and is rarely found in the form of its own minerals. Seven minerals are known, in which its concentration is more than 1%, among them: Cu2 (Cu, Ge, Ga, Fe, Zn)2 (S, As)4X X (6.2-10.2% Ge), rhenierite (Cu, Fe)2 (Cu, Fe, Ge, Ga, Zn)2 X X (S, As)4 (5.46-7.80% Ge) and argyrodite Ag8GeS6 (3/55-6.93% Ge) . G. also accumulates in caustobioliths (humic coals, oil shale, oil). The crystalline modification of Gel, which is stable under normal conditions, has a cubic structure like diamond, with a period a = 5.65753 A (Gel).
Density of germanium (temp. 25°C) 5.3234 g/cm3, melting point 937.2°C; bp 2852° C; heat of fusion 104.7 cal/g, heat of sublimation 1251 cal/g, heat capacity (temperature 25°C) 0.077 cal/g deg; coefficient thermal conductivity, (temperature 0° C) 0.145 cal/cm sec deg, temperature coefficient. linear expansion (temperature 0-260° C), 5.8 x 10-6 deg-1. When melting, germanium decreases in volume (by about 5.6%), its density increases by 4% h When high blood pressure diamond-like modification. Germanium undergoes polymorphic transformations, forming crystalline modifications: a tetragonal structure of the B-Sn type (GeII), a body-centered tetragonal structure with periods a = 5.93 A, c = 6.98 A (GeIII) and a body-centered cubic structure with a period a = 6, 92 A(GeIV). These modifications are distinguished by higher density and electrical conductivity compared to GeI.
Amorphous germanium can be obtained in the form of films (about 10-3 cm thick) by steam condensation. Its density is less than the density of crystalline crystalline crystals. The structure of the energy bands in a crystalline crystalline crystal determines its semiconductor properties. The width of the band gap is equal to 0.785 eV (temperature 0 K), specific electrical resistance(temperature 20°C) 60 ohm cm and with increasing temperature it decreases significantly according to an exponential law. Impurities give G. the so-called. impurity conductivity of electronic (impurities of arsenic, antimony, phosphorus) or hole (impurities of gallium, aluminum, indium) type. The mobility of charge carriers in gravity (temperature 25°C) for electrons is about 3600 cm2/per second, for holes - 1700 cm2/per second, the intrinsic concentration of charge carriers (temperature 20°C) is 2.5. 10 13 cm-3. G. diamagnetic. When melted, it transforms into a metallic state. Germanium is very brittle, its Mohs hardness is 6.0, its microhardness is 385 kgf/mm2, its compressive strength (temperature 20°C) is 690 kgf/cm2. As the temperature increases, the hardness decreases; above a temperature of 650° C, it becomes plastic and gives way to fur. processing. Germanium is practically inert to air, oxygen and non-oxidizing electrolytes (if there is no dissolved oxygen) at temperatures up to 100° C. Resistant to the action of salt and dilute sulfuric acid; dissolves slowly in concentrated sulfuric and nitric acids when heated (the resulting film of dioxide slows down the dissolution), dissolves well in aqua regia, in solutions of hypochlorites or alkali metal hydroxides (in the presence of hydrogen peroxide), in alkali melts, peroxides, nitrates and carbonates of alkali metals.
Above temperatures of 600° C, it is oxidized in air and in a stream of oxygen, forming GeO oxide and dioxide (Ge02) with oxygen. Germanium oxide is a dark gray powder that sublimes at a temperature of 710° C, slightly dissolves in water with the formation of a weak germanite compound (H2Ge02), salts (germanites) are not stable. GeO easily dissolves in compounds to form divalent G salts. Germanium dioxide - powder white, exists in several polymorphic modifications that differ greatly in chemical properties. Saints: the hexagonal modification of the dioxide is relatively well soluble in water (4.53 zU at a temperature of 25 ° C), alkali solutions and the like, the tetragonal modification is practically insoluble in water and inert to them. Dissolving in alkalis, dioxide and its hydrate form metagermanate (H2Ge03) and orthogermanate (H4Ge04) salts - germanates. Alkali metal germanates are soluble in water, while other germanates are practically insoluble; freshly precipitated ones dissolve in mineral compounds. G. easily combines with halogens, forming when heated (about 250 ° C) the corresponding tetrahalogenides - non-salt-like compounds that are easily hydrolyzed by water. Known g. - dark brown (GeS) and white (GeS2).
Germanium is characterized by compounds with nitrogen - brown nitride (Ge3N4) and black nitride (Ge3N2), characterized by a lower chemical. durability. With phosphorus, G. forms a low-resistant phosphide (GeP) of black color. It does not interact with carbon and does not fuse; with silicon it forms a continuous series of solid solutions. Germanium, as an analogue of carbon and silicon, is characterized by the ability to form germanium hydrogens of the GenH2n + 2 type (germanes), as well as solid compounds of the GeH and GeH2 types (germenes). Germanium forms metal connections() and with plural metals. The extraction of germanium from raw materials involves obtaining a rich germanium concentrate, and from it a high purity. In prom. On a large scale, germanium is obtained from tetrachloride, using during purification its high volatility (for isolation from concentrate), low in concentrated hydrochloric acid and high in organic solvents (for purification from impurities). Often, for enrichment, the high volatility of lower sulfides and oxides is used, which easily sublimate.
To obtain semiconductor germanium, directional crystallization and zone recrystallization are used. Monocrystalline germanium is obtained by drawing from a melt. During the growing process, G. is doped with special. additives, regulating certain properties of the single crystal. G. is supplied in the form of ingots with a length of 380-660 mm and cross section up to 6.5 cm2. Germanium is used in radio electronics and electrical engineering as a semiconductor material for the manufacture of diodes and transistors. Lenses for infrared optics devices, nuclear radiation dosimeters, X-ray spectroscopy analyzers, sensors using the Hall effect, and converters of radioactive decay energy into electrical energy are made from it. Germanium is used in microwave attenuators and resistance thermometers operated at the temperature of liquid helium. The G. film applied to the reflector is characterized by high reflectivity and good corrosion resistance. germanium with some metals, characterized by increased resistance to acidic aggressive environments, are used in instrument making, mechanical engineering and metallurgy. Hemanium and gold form a low-melting eutectic and expand upon cooling. G. dioxide is used for the manufacture of special products. glasses characterized by high coefficient. refraction and transparency in the infrared part of the spectrum, glass electrodes and thermistors, as well as enamels and decorative glazes. Germanates are used as activators of phosphorus and phosphors.
Germanium — chemical element of the periodic system of chemical elements D.I. Mendeleev. And denoted by the symbol Ge, germanium is a simple substance gray-white and has the hard characteristics of metal.
Content in the earth's crust is 7.10-4% by weight. refers to trace elements, due to the piles of reactivity to oxidation in a free state, it is not found as pure metal.
Finding germanium in nature
Germanium is one of the three chemical elements predicted by D.I. Mendeleev based on their position in the periodic table (1871).
It belongs to rare trace elements.
Currently, the main sources of industrial production of germanium are waste from zinc production, coal coking, ash of some types of coal, in silicate impurities, sedimentary iron rocks, in nickel and tungsten ores, peat, oil, geothermal waters and in some algae.
Main minerals containing germanium
Plumbohermatite (PbGeGa) 2 SO 4 (OH) 2 +H 2 O content up to 8.18%
yargyrodite AgGeS6 contains from 3.65 to 6.93% germany
rhenierite Cu 3 (FeGeZn)(SAs) 4 contains from 5.5 to 7.8% germanium.
In some countries, germanium is obtained as a by-product of the processing of certain ores such as zinc-lead-copper. Germanium is also obtained in the production of coke, as well as in brown coal ash with a content of 0.0005 to 0.3% and in hard coal ash with a content of 0.001 to 1-2%.
Germanium as a metal is very resistant to atmospheric oxygen, oxygen, water, some acids, dilute sulfuric and hydrochloric acid. But it reacts very slowly with concentrated sulfuric acid.
Germanium reacts with nitric acid HNO 3 and aqua regia, reacts slowly with caustic alkalis to form germanate salt, but with the addition of hydrogen peroxide H 2 O 2 the reaction proceeds very quickly.
When exposed high temperatures above 700 °C germanium is easily oxidized in air to form GeO 2 , easily reacts with halogens, thereby producing tetrahalogenites.
It does not react with hydrogen, silicon, nitrogen and carbon.
There are known volatile compounds of germanium with the following characteristics:
Germany hexahydride -digerman, Ge 2 H 6 - flammable gas, with long-term storage decomposes in the light, turning yellow then brown turning into a solid dark - Brown, decomposes with water and alkalis.
Germany tetrahydride, monogermane - GeH 4 .
Application of germanium
Germanium, like some others, has the properties of so-called semiconductors. Based on their electrical conductivity, everything is divided into three groups: conductors, semiconductors and insulators (dielectrics). The specific electrical conductivity of metals is in the range 10V4 - 10V6 Ohm.cmV-1, the given division is arbitrary. However, you can specify fundamental difference in the electrical properties of conductors and semiconductors. For the former, the electrical conductivity decreases with increasing temperature, while for semiconductors it increases. At temperatures close to absolute zero, semiconductors turn into insulators. As is known, metal conductors exhibit superconducting properties under such conditions.
Semiconductors can be various substances. These include: boron, (or
The chemical element germanium is in the fourth group (main subgroup) in the periodic table of elements. It belongs to the family of metals, its relative atomic mass is 73. By mass, the content of germanium in the earth's crust is estimated at 0.00007 percent by mass.
History of discovery
The chemical element germanium was established thanks to the predictions of Dmitry Ivanovich Mendeleev. It was they who predicted the existence of eca-silicon and gave recommendations for its search.
Believed that this metal element found in titanium and zirconium ores. Mendeleev tried to find this chemical element on his own, but his attempts were unsuccessful. Only fifteen years later, a mineral called argyrodite was found at a mine located in Himmelfürst. This compound owes its name to the silver found in this mineral.
The chemical element germanium in the composition was discovered only after a group of chemists from the Freiberg Mining Academy began research. Under the leadership of K. Winkler, they found that the share of oxides of zinc, iron, as well as sulfur and mercury accounted for only 93 percent of the mineral. Winkler suggested that the remaining seven percent came from a chemical element unknown at the time. After further chemical experiments, germanium was discovered. The chemist reported his discovery in a report and presented the information obtained about the properties of the new element to the German Chemical Society.
The chemical element germanium was presented by Winkler as a non-metal, by analogy with antimony and arsenic. The chemist wanted to call it neptunium, but this name was already in use. Then they began to call it germanium. The chemical element discovered by Winkler sparked serious debate among the leading chemists of the time. The German scientist Richter suggested that this is the same ecasilicium that Mendeleev spoke about. After some time, this assumption was confirmed, which proved the viability of the periodic law created by the great Russian chemist.
Physical properties
How can germanium be characterized? The chemical element has 32 serial number in Mendeleev. This metal melts at 937.4 °C. The boiling point of this substance is 2700 °C.
Germanium is an element that was first used in Japan for medical purposes. After numerous studies of organogermanium compounds carried out on animals, as well as in human studies, it was possible to discover the positive effects of such ores on living organisms. In 1967, Dr. K. Asai discovered the fact that organic germanium has a huge range of biological effects.
Biological activity
What is the characteristic chemical element Germany? It is capable of transporting oxygen throughout all tissues of a living organism. Once in the blood, it behaves in a similar way to hemoglobin. Germanium guarantees the full functioning of all systems of the human body.
It is this metal that stimulates the proliferation of immune cells. It, in the form of organic compounds, allows the formation of gamma interferons, which suppress the proliferation of microbes.
Germanium prevents the formation of malignant tumors and prevents the development of metastases. Organic compounds of this chemical element contribute to the production of interferon, a protective protein molecule that is produced by the body as a protective reaction to the appearance of foreign bodies.
Areas of use
The antifungal, antibacterial, and antiviral properties of germanium have become the basis for its areas of application. In Germany, this element was mainly obtained as a by-product of processing non-ferrous ores. Different ways, which depend on the composition of the feedstock, isolated germanium concentrate. Its composition contained no more than 10 percent metal.
How exactly is germanium used in modern semiconductor technology? The characteristics of the element given earlier confirm the possibility of its use for the production of triodes, diodes, power rectifiers, and crystal detectors. Germanium is also used in the creation of dosimetric instruments, devices that are necessary for measuring the strength of constant and alternating magnetic fields.
A significant area of application of this metal is the manufacture of infrared radiation detectors.
Promising is the use of not only germanium itself, but also some of its compounds.
Chemical properties
Germanium at room temperature Quite resistant to moisture and air oxygen.
In the series - germanium - tin) there is an increase in the reducing ability.
Germanium is resistant to solutions of hydrochloric and sulfuric acids; it does not interact with alkali solutions. Moreover, this metal dissolves quite quickly in aqua regia (seven nitric and hydrochloric acids), as well as in an alkaline solution of hydrogen peroxide.
How to give full description chemical element? Germanium and its alloys must be analyzed not only for physical and chemical properties, but also for areas of application. The process of germanium oxidation with nitric acid proceeds quite slowly.
Being in nature
Let's try to characterize the chemical element. Germanium is found in nature only in the form of compounds. Among the most common germanium-containing minerals in nature, we highlight germanite and argyrodite. In addition, germanium is present in zinc sulfides and silicates, and in small quantities it is found in various types coal.
Harm to health
What effect does germanium have on the body? Chemical element, electronic formula which has the form 1e; 8 e; 18th; 7 e, may have a negative effect on the human body. For example, when loading germanium concentrate, grinding, as well as loading the dioxide of this metal, occupational diseases may appear. Other sources harmful to health include the process of melting germanium powder into bars and producing carbon monoxide.
Adsorbed germanium can be quickly eliminated from the body, mostly through urine. Currently, there is no detailed information on how toxic inorganic germanium compounds are.
Germanium tetrachloride has an irritating effect on the skin. In clinical trials, as well as with long-term oral administration of cumulative quantities that reached 16 grams of spirogermanium (an organic antitumor drug), as well as other germanium compounds, nephrotoxic and neurotoxic activity of this metal was discovered.
Such dosages are generally not typical for industrial enterprises. Those experiments that were carried out on animals were aimed at studying the effect of germanium and its compounds on a living organism. As a result, it was possible to establish a deterioration in health due to inhalation of a significant amount of germanium metal dust, as well as its dioxide.
Scientists have discovered serious morphological changes in the lungs of animals that are similar to proliferative processes. For example, significant thickening of the alveolar sections was detected, as well as hyperplasia of the lymphatic vessels around the bronchi, and thickening of the blood vessels.
Germanium dioxide is not irritating to the skin, but direct contact of this compound with the membrane of the eye leads to the formation of germanic acid, which is a serious eye irritant. With prolonged intraperitoneal injections, serious changes in the peripheral blood were detected.
Important facts
The most harmful compounds of germanium are germanium chloride and hydride. The latter substance provokes serious poisoning. As a result of a morphological examination of the organs of animals that died during the acute phase, significant disturbances in the circulatory system were shown, as well as cellular modifications in the parenchymal organs. Scientists have concluded that the hydride is a multi-purpose poison that affects nervous system, inhibits the peripheral circulatory system.
Germanium tetrachloride
He is a strong irritant respiratory system, eyes, skin. At a concentration of 13 mg/m3, it is capable of suppressing the pulmonary response at the cellular level. As the concentration of this substance increases, serious irritation of the upper respiratory tract and significant changes in the rhythm and frequency of breathing are observed.
Poisoning with this substance leads to catarrhal-desquamative bronchitis and interstitial pneumonia.
Receipt
Since in nature germanium is present as an impurity in nickel, polymetallic, and tungsten ores, several steps are carried out to isolate pure metal in industry. labor-intensive processes related to ore dressing. Germanium oxide is first isolated from it, then it is reduced with hydrogen at elevated temperature until simple metal is obtained:
GeO2 + 2H2 = Ge + 2H2O.
Electronic properties and isotopes
Germanium is considered an indirect gap typical semiconductor. The value of its dielectric statistical constant is 16, and the value of its electron affinity is 4 eV.
In a thin film of doped gallium, germanium can be given a superconducting state.
There are five isotopes of this metal present in nature. Of these, four are stable, and the fifth undergoes double beta decay, the half-life is 1.58 × 10 21 years.
Conclusion
Currently, organic compounds of this metal are used in different areas industry. Transparency in the infrared spectral region of metallic germanium of ultra-high purity is important for the manufacture of optical elements of infrared optics: prisms, lenses, optical windows of modern sensors. The most common area of use of germanium is the creation of optics for thermal imaging cameras, which operate in the wavelength range from 8 to 14 microns.
Similar devices are used in military equipment for infrared guidance systems, night vision, passive thermal imaging, fire protection systems. Also germanium has high rate refraction, which is necessary for anti-reflective coating.
In radio engineering, transistors based on germanium have characteristics that in many respects exceed those of silicon elements. The reverse currents of germanium elements are significantly higher than those of their silicon counterparts, which makes it possible to significantly increase the efficiency of such radio devices. Considering that germanium is not as common in nature as silicon, silicon semiconductor elements are mainly used in radio devices.
GERMANIUM, Ge (from Latin Germania - Germany * a. germanium; n. Germanium; f. germanium; i. germanio), is a chemical element of group IV of the periodic system of Mendeleev, atomic number 32, atomic mass 72.59. Natural germanium consists of 4 stable isotopes 70 Ge (20.55%), 72 Ge (27.37%), 73 Ge (7.67%), 74 Ge (36.74%) and one radioactive 76 Ge (7. 67%) with a half-life of 2.10 6 years. Discovered in 1886 by the German chemist K. Winkler in the mineral argyrodite; was predicted in 1871 by D. N. Mendeleev (exasilicon).
Germanium in nature
Germanium belongs to. The abundance of germanium is (1-2).10 -4%. It is found as an impurity in silicon minerals, and to a lesser extent in minerals and. Germanium's own minerals are very rare: sulfosalts - argyrodite, germanite, renerite and some others; double hydrated oxide of germanium and iron - schottite; sulfates - itoite, fleischerite and some others. They have practically no industrial significance. Germanium accumulates in hydrothermal and sedimentary processes, where the possibility of separating it from silicon is realized. IN increased quantities(0.001-0.1%) found in, and. Sources of germanium include polymetallic ores, fossil coals, and some types of volcanic-sedimentary deposits. The main amount of germanium is obtained as a by-product from tar waters during the coking of coals, from the ash of thermal coals, sphalerite and magnetite. Germanium is extracted by acid, sublimation in a reducing environment, fusion with caustic soda, etc. Germanium concentrates are processed hydrochloric acid when heated, the condensate is purified and undergoes hydrolytic decomposition to form dioxide; the latter is reduced by hydrogen to metallic germanium, which is purified by fractional and directional crystallization methods and zone melting.
Application of germanium
Germanium is used in radio electronics and electrical engineering as a semiconductor material for the manufacture of diodes and transistors. Lenses for IR optics, photodiodes, photoresistors, nuclear radiation dosimeters, X-ray spectroscopy analyzers, radioactive decay energy converters into electrical energy, etc. are made from germanium. Alloys of germanium with certain metals, characterized by increased resistance to acidic aggressive environments, are used in instrument making, mechanical engineering and metallurgy. Some alloys of germanium with other chemical elements are superconductors.
At the time of the creation of the periodic table, germanium had not yet been discovered, but Mendeleev predicted its existence. And 15 years after the report, an unknown mineral was discovered in one of the Freiberg mines, and in 1886 a new element was isolated from it. The credit goes to the German chemist Winkler, who gave the element the name of his homeland. Even with many useful properties Germany, among which there was a place for medicinal ones, they began to use it only at the beginning of the Second World War, and even then not very actively. Therefore, even now it cannot be said that the element has been well studied, but some of its abilities have already been proven and are being successfully used.
The healing properties of germanium
The element is not found in its pure form, its isolation is labor-intensive, so at the first opportunity it was replaced with cheaper components. At first it was used in diodes and transistors, but silicon turned out to be more convenient and accessible, so the study of the chemical properties of germanium continued. Now it is part of thermoelectric alloys and is used in microwave devices and infrared technology.
Medicine also became interested in the new element, but significant result was obtained only in the late 70s of the last century. Japanese specialists managed to discover medicinal properties germanium and outline ways of their use. After testing on animals and clinical observations of the effect on humans, it turned out that the element is capable of:
- stimulate;
- deliver oxygen to tissues;
- fight tumors;
- increase the conductivity of nerve impulses.
The difficulty of use lies in the toxicity of germanium in large doses, so a drug was required that could provide positive influence on certain processes in the body with minimal harm. The first was Germanium-132, which helps improve a person’s immune status and helps avoid oxygen deficiency in the event of a drop in hemoglobin levels. Experiments have also shown the effect of the element on the production of interferons, which resist rapidly dividing (tumor) cells. The benefit is observed only when administered orally, wearing jewelry with germanium it will have no effect.
A deficiency of germanium reduces the body's natural ability to resist external influences, which leads to various violations. The recommended daily dose is 0.8-1.5 mg. Get necessary element possible with regular consumption of milk, salmon, mushrooms, garlic and beans.
Please note that we receive germanium in any quantity and form, incl. in the form of scrap. You can sell germanium by calling the phone number in Moscow indicated above.
Germanium is a brittle semimetal silver-white color, opened in 1886. This mineral is not found in its pure form. It is found in silicates, iron and sulfide ores. Some of its compounds are toxic. Germanium is widely used in the electrical industry, where its semiconductor properties are useful. It is indispensable in the production of infrared and fiber optics.
What properties does germanium have?
This mineral has a melting point of 938.25 degrees Celsius. Scientists still cannot explain the indicators of its heat capacity, which makes it indispensable in many fields. Germanium has the ability to increase its density when melted. It has excellent electrophysical properties, which makes it an excellent indirect gap semiconductor.
If speak about chemical properties This semimetal, it should be noted that it is resistant to acids and alkalis, water and air. Germanium dissolves in a solution of hydrogen peroxide and aqua regia.
Germany mining
A limited amount of this semi-metal is currently mined. Its deposits are significantly smaller compared to deposits of bismuth, antimony, and silver.
Due to the fact that the proportion of this mineral in the earth’s crust is quite small, it forms its own minerals due to the introduction of other metals into the crystal lattices. The highest germanium content is observed in sphalerites, pyrargyrite, sulfanite, non-ferrous and iron ores. It is found, but much less frequently, in oil and coal deposits.
Uses of germanium
Despite the fact that germanium was discovered quite a long time ago, it began to be used in industry approximately 80 years ago. The semimetal was first used in military production for the manufacture of certain electronic devices. In this case, it found application as diodes. Now the situation has changed somewhat.
The most popular areas of application of germanium include:
- production of optics. The semimetal has become indispensable in the manufacture of optical elements, which include optical sensor windows, prisms, and lenses. The transparency properties of germanium in the infrared region came in handy here. Semi-metal is used in the production of optics for thermal imaging cameras, fire systems, and night vision devices;
- production of radio electronics. In this area, the semimetal was used in the manufacture of diodes and transistors. However, in the 70s, germanium devices were replaced with silicon ones, since silicon made it possible to significantly improve the technical and operational characteristics of manufactured products. Increased resistance to temperature influences. In addition, germanium devices made a lot of noise during operation.
Current situation with germanium
Currently, the semimetal is used in the production of microwave devices. Germanium telleride has proven itself well as a thermoelectric material. Germanium prices are now quite high. One kilogram of germanium metal costs $1,200.
Buying Germany
Silver-gray germanium is rare. The brittle semimetal has semiconductor properties and is widely used to create modern electrical appliances. It is also used to create high-precision optical instruments and radio equipment. Germanium is of great value both in the form of pure metal and in the form of dioxide.
The Goldform company specializes in the purchase of germanium, various scrap metal, and radio components. We offer assistance with material assessment and transportation. You can send germanium by mail and receive your money in full.
