Diamond is the most stable form of carbon. Because of the extremely strong covalent connection between the carbon atoms, it has outstanding physical characteristics. Diamond has the highest hardness and heat conductivity of any natural or synthetic substance known to man. Its resistance to corrosion makes it useful for many applications including cutting tools, wear-resistant coatings, and medical devices. Diamond was first discovered in the year 1847 by Charles Thomas Caratini while searching for gold in the Sierra Nevada Mountains near the town now called De Beers. He returned home with a diamond that he had found on one of his claims. This diamond turned out to be very rare because only iron ore along with quartz sand contains significant amounts of diamond. Only under special conditions can carbon become bonded into a crystal structure without any other elements being involved. Over time this bond becomes stronger due to high pressure and temperature resulting in a diamond. On the surface of a diamond molecule are three carbon atoms connected together with four other electrons in what is called an sp3 hybrid orbital. These six electrons are distributed over the entire diamond molecule. The next layer out is the outermost shell of an atom which consists of two electrons in an s orbital. There are eight electrons in all in the 2s orbital which means that it is completely filled.