Iridium is an element that originates in the stars. A supernova event is responsible for the creation of this element and it does not occur as a result of fusion.
In the Earth's crust, iridium is quite rare and most of what humans use is a byproduct of copper and nickel refining. Those people refining these metals use processing tanks and iridium turns up in the mud within these tanks. It is in gravel deposits in nature when those deposits have platinum and osmium ores. Canada is the most common mining area; however, worldwide, people find about 3 tons of iridium each year.