Yttrium, a scarce mineral, existed as one of several ores and minerals being taken from the crust of Nar Kreeta, a rocky planet within Hutt Space, during the era of the Galactic Civil War fought between the Galactic Empire and the Rebel Alliance.
Vast underground deposits of yttrium were also discovered on Guiteica, a planet situated in the Kadok Regions of Wild Space's. Around 2 ABY, Vulca Minerals's aggressive attempts to negotiate yttrium mining rights with the native Bitthævrian species of Guiteica resulted in the m'Yalfor'ac Order, the Bitthævrian's main continental army, almost killing the company's Team Commander. Following that event, Kadok Resources took control of all of Guiteica's exported goods.
Yttrium's introduction to the Star Wars universe occurred in Alliance Intelligence Reports, a 1995 sourcebook for Star Wars: The Roleplaying Game by West End Games. In reality, yttrium is a chemical element and a rare-earth metal sourced mainly from rare-earth ores, finding use in a wide array of industrial applications.