WHAT IS GERMANIUM?
Germanium is one of the carbon family members and it belongs to the group 4B in periodic table
Standard atomic weigh: 72.59
Boiling point: 3106 K
D.I. Mendeleev predicted the existence of Germanium in 1821(1871) as ekasilicon and the element was discovered by German chemists, C.Winkler and A. Breithaupt in Argyrodite in 1886, and was named Germanium from the Latin word Germania, Germany.
It is found in a few minerals like argyrodite and germanite, but the resources are limited. It is thinly, widely distributed in the Earth’s crust and is recovered from combustion by-products of certain coals such as sphalerite and sometimes exists as being absorbed in plants.
The element is a gray-white metalloid. In pure state, the element is crystalline and brittle and its Mohs hardness is 6. It is a typical semiconductor and is assumed as a intrinsic semiconductor. If it contains group III-V extrinsic elements, it becomes p and n type semiconductor. Its crystallographic structure is a diamond cubic crystal.
How to extract Germanium
(This paragraph in italic is from http://www.chemistryexplained.com/elements/C-K/Germanium.html)
Germanium in zinc ores is heated in the presence of chlorine gas. Germanium chloride (GeCl 4 ) is formed:
Pure germanium metal is then produced by passing an electric current through molten (melted) germanium chloride:
This method produces very pure germanium. It is possible to buy germanium that is 99.9999 percent pure. This level of purity is needed in order to use the metal in the production of semiconductors.