Osmium is a dense, bluish-white metal that belongs to the platinum group of elements. It has the highest density of all naturally occurring elements, making it very heavy. Osmium is primarily used in applications that require durability and hardness, such as in fountain pen nibs, electrical contacts, and as a catalyst in chemical reactions. This element is represented by the symbol Os on the periodic table and has an atomic number of 76. Osmium is not commonly found in nature in its pure form; instead, it is usually extracted from ores containing other platinum group metals.