In the Movie Stargate, what material was the stargate actually made of? They mentioned the material commonly as 'Mineral'. Has it been mentioned anywhere else in the Stargate Universe?
Stargates are made of naqahdah, a fictitious superheavy metal.
Stargate was made of naquadah, which is fictional superheavy mineral. Naquadah is superconductive at normal temperature (around 20°C). Although no other materials are mentioned, it is probable that Stargate is made of other materials as well since it would require very elaborate inner workings and systems to operate. This is because Stargate does not simply create stable wormhole, but rather creates very small one and disintegration field that disintegrates objects to fit this thin wormhole. That would be why objects can travel only one direction (particles would collide) and electromagnetic waves can travel both ways. In reality, elements with atomic number as high as naquadah would be extremely unstable and theory therefore is, that it must be placed somewhere in the "isle of stability" in the periodic table of elements.