This is a non-metal and it is a structural element of all biomolecules and living beings. Three naturally occurring allotropes of this element are known to exist: amorphous, graphite and diamond.
This is a transition metal. This is a metal of the platinum family and it is the most corrosion-resistant metal known. It is used in the production of the alloys with osmium and platinum and in the production of crucibles and devices requiring high temperatures.