naquadria
THE STARGATE OMNIPEDIA
NAQUADRIA
A variant of naquadah that is far more powerful, but also very unstable and dangerous. The only known planet where the element is found is Langara, especially on the Kelownan continent. Naquadria is believed to be artificial, created by the Goa'uld Thanos some 3,000 years ago in experiments that nearly destroyed the planet.

Led by Jonas Quinn, the Kelownans eventually discovered the explosive process that transforms ordinary naquadah into naquadria, and used the Kelownan D.U.E.V. to tunnel below the surface of the planet and stop a chain reaction that was transforming a massive vein of naquadah into its more volatile derivative, threatening to annihilate the planet.

Earth relies on naquadria to power the hyperspace engines on its ships, allowing them interstellar travel for the first time.

KEY EPISODE(S) -
Meridian - SG-1 visits Kelowna, a world attempting to make a weapon of mass destruction with naquadria.
Redemption, Part 1 - O'Neill and Carter pilot the first ship capable of opening a hyperspace window, thanks to the power of naquadria. The test flight is a failure, due to the mineral's inherent instability.
Shadow Play - The team returns to Kelowna, where scientists have completed the naquadria bomb -- and the government plans to use it in a pre-emptive strike against their neighbors. SG-1 finds a large supply of naquadria.
Prometheus - Having apparently overcome the instability of naquadria, the X-303 makes the first successful extended flight through hyperspace by an Earth-made ship.
Homecoming - The naquadria mine on Kelowna is run dry after Anubis's forces arrive to take whatever is left. Kelowna and the planet's other nations hand over their entire supplies of the mineral.
Fallout - Carter and Teal'c return to Kelowna to solve a new naquadria problem: massive veins of the mineral beneath the surface of the planet threaten to obliterate the world.