Naquadah is the element from which the stargate is made. Unknown on Earth, it is an extremely dense dark gray quartz-like metal, and the basis of Goa'uld technology. Although it does not occur naturally in our solar system, most Goa'uld worlds have a high incidence of naquadah, and SG-1 has encountered several worlds with naquadah resources including Abydos, Edora, Langara, P2C-257, P3R-636, P4S-237, P5S-117, P3X-403, and P8X-412.
The SGC seeks naquadah resources for countless potential military and scientific applications. Using the technology of Orban, Carter has constructed a viable naquadah reactor which has enormous potential as an alternative power source.
Naquadah will also greatly magnify the explosive energy of nuclear ordinance. In an early test of a naquadah-enhanced weapon on P3S-452, the device reacted with the naquadah in the planet's soil and resulted in a chain reaction that caused high levels of radiation to translate back through the stargate. The naquadah-enhanced warhead developed to deflect the asteroid from Earth's path, the most powerful warhead created at the time, was equivalent to 1200 megatons, or one billion tons of TNT. The Goa'uld have also used naquadah to enhance explosive weapons. Sekhmet's ark is a form of a Goa'uld naquadah bomb. Ba'al saw to it that the construction of the Halcyon Tower in Seattle was laced with naquadah so that it could be detonated, and Arkad had planned an attack against Earth using cargo ships loaded with naquadah.
Naquadah is also required in the construction of F-302, BC-303, and BC-304 spacecraft. When resonance scans of P3X-403 revealed as much as 53,000 metric tons of naquadah ore, the SGC negotiated with the native Unas for mining rights. The planet is now a main source for Earth's naquadah supply. Earth has also developed hand-held scanners capable of detecting the presence of naquadah, and the Prometheus and Odyssey have instruments capable of detecting naquadah from orbit.
Naquadah is also an essential element of Goa'uld physiology, and the Goa'uld and former hosts retain traces of naquadah in their blood which can be detected by others with naquadah in their systems. Certain Goa'uld devices such as the ribbon device or healing device require the presence of naquadah in the blood for activation.
Naquadah is related to naquadria, a radioactive variation of the mineral. The Goa'uld Thanos on P2S-4C3 first discovered a process which would convert raw naquadah into naquadria while it is still in the ground. Naquadria is highly unstable, however, and in a few thousand years' time it will decay back into naquadah.
First Identified: Singularity