Vigamian blue steel is an incredibly rare metal found only in the Blue Forest (now Blue Desert) on the Planet Vigam. Virtually indistinguishable from lapis lazuli in its ore form, Vigamian blue steel shines a distinctive shade of electric blue when refined. Blue steel is essentially a natural super metal, as it is many times harder than even the hardest steel, but unlike many harder alloys, do not lose their pliability and become brittle, allowing blue steel to serve as a much more resilient alternative to bronze, iron, or steel in weaponmaking.
Historically, blue steel has been used in weapons and armor by all of the various sentients of Vigam for millennia, from the Arachna of The Hive to the Burrowers of the far south, and has been Vigam's most valuable export for its entire history, as the extremely limited supply makes it very expensive. Early in its history, the Aurean Dominate invaded and conquered most of Vigam in part to secure a supply of blue steel, which they used for many of their weapons and much of their armor. However, as the millennia wore on, Aurea's control over Vigam weakened, more and more of the planet reasserted its independence, and before long, Aurea only controlled as far north as Fort Rachias, nowhere near the Blue Forest. As a result, Aurea's supply of blue steel shrank drastically and it was eventually retired from most military use, replaced by steel and other cheaper metals. As of the year 0 BR, the Aureans only used it for helmets.
After their industrial revolution, the Ishgas took an interest in blue steel as well, using it for starship hulls and as lightbulb filaments, since it had a much higher melting point than tungsten. In the year 56 BR, the Ishgas led an expedition under Sir Trevor Johnson to start a mining enterprise in the Blue Forest to extract blue steel for as little cost as possible. Although many Ishgas came to Vigam to participate, the company also employed many Vigamians, and soon began outcompeting native Vigamian mining businesses and wrecking the local economy. King Natoli I of Vigam tried to petition the Ishgas to dismantle their operation, but they refused, and in 45 BR, King Natoli's soldiers arrested Sir Trevor Johnston and detained many of the company's executives, which Ishga responded to by declaring war and immediately blockading the planet with starships. Caputus Vigamius was subject to an orbital bombardment, a numerically inferior Ishga force crushed multiple Vigamian armies, and Natoli sued for peace within a month. The resulting Treaty of New Carekion resulted in Vigam ceding the Blue Forest to the Ishgas, giving them total control of Vigam's blue steel reserves and depriving the planet of its chief export.
Some time after this, the Ishgas figured out how to make Azracium, an even stronger, silvery-blue alloy made by combining blue steel with titanium and chromium. This material, however, was far too brittle to be of much use in weapon blades, instead mostly being used for starship hulls, industrial equipment, and sword hilts.
During the Great Tatian Coup, all of Vigam save for the Blue Forest fell under Tatian control immediately. The Blue Forest would not be spared Tatian rule for long, however, as the Tatians desperately sought blue steel to compete with the superior Ishga Fleet that was built almost entirely from it. Less than a month after the coup, Tate personally landed on Vigam with an invasion force large enough to capture five star systems, rapidly overwhelmed the Ishga garrison of the Blue Forest, and began a colossal strip mining operation that would completely destroy the fragile ecosystem that was the Blue Forest, creating the Blue Desert that sits there today in the process. In addition to displacing millions of sentients, this ecological disaster led to the rapid extinction or extirpation of many species of wildlife, such as aurochs, red deer, Tauropean gliders, wild boars, wolverines, Aurean giant beavers, beelzebufo, and wildcats. To fill the void left by this crisis, the Tatians introduced species from the Hurrian Desert further south, such as arthropleura, ant griffins, desert moths, desert gliders, goatweaver tarantulas, sand dragons, and ornithomimus. The blue sands that form the Blue Desert are made up of blue steel ore dust that was churned up during the massive mining operation. After the destruction of the Tatian Empire at the end of the Tatian War, the Blue Desert was returned to Vigam, which controls it to this day.