Selenium

What is selenium?
Discovered by Jöns Jakob Berzelius and Johan Gottlieb Gahn of Sweden, selenium is the 34th element in the periodic table. It's name means 'moon' in Greek. It is a member of the sulfur group of nonmetallic elements and it is very similar to this element in form and compounds.

 Selenium has 'photovoltaic action', where light is converted directly to electricity. Selenium has many different forms, but is most commonly found in a crystalline form, shown to the right in form of a red vase.

Amorphus selenium is either red (powder) or black (vitreous). Crystalline selenium is usually deep red, and crystalline hexagonal selenium, which is the most stable type, is gray with a metallic luster.

What is it used for?
Selenium is most commonly used in xerography to copy documents and also in photographic toner. It is used widely in many glass products to color glass ruby red (as seen above). Because of it's ability to convert AC electricity to DC, it is widely used in rectifiers. Selenium is also used as an additive to stainless steel.


Where is it found?
Selenium is found in many types of soils, and is also found in the minerals crooksite and clausthalite. It can also be recovered by roasting mud with soda or sulfuric acid. or by smiting soda and niter.