Naquadah is a very rare chemical element with the symbol NQ and has the atomic number 125. In its purest form, it is a colorless invisible gas however creating gaseous Naquadah is near impossible. For the longest time we the Tau'ri thought that Naquadah was just a mineral not knowing that what we considered the mineral Naquadah was the element Naquadah fused with some tiny bit of Sturinium.
Naquadah is a super-heavy element which has superconducting properties. It can store massive amounts of energy and is extremely hard. It gives off a unique energy signature that the Goa'uld, former hosts, Jaffa, Tok'ra, and Cassandra Fraiser can detect. However, large doses of drugs can counter this. Hand-held sensors and those on the Prometheus can detect the signature. The energy stored in Naquadah can be released rather efficiently. Small amounts of Naquadah can be absorbed into the blood streams of some creatures. Allied with the host body's bio-electrical impulses, the energy contained within the Naquadah in the bloodstream of host and symbiote renders these Goa'uld devices operable when touched. Because of the Naquadah in her blood, Major Samantha Carter was resistant to anesthesia. Radio signals cannot pierce large amounts of Naquadah.
Naquadah is capable of repeatedly handling an active wormhole, whereas Titanium only lasts several minutes under similar conditions. The hardest known substance in the universe is the Asgard-created alloy, consisting of Carbon, Trinium, and Naquadah. Liquid Naquadah is capable of firing powerful pulses of energy repeatedly. An isotopic variant of Naquadah called Naquadria stores much more power, but is radioactive. It was believed to have been created artificially by the Goa'uld Thanos on Langara, the first planet on which it was discovered and the only one currently known to possess it. P4X-351 and the Icarus-like planet also possessed Naquadria cores, but both were destroyed in the two known instances of dialing the nine-chevron address of the Ancient ship Destiny's Stargate. Carter theorizes that the substance can be used to solve hyperdrive technology as well as shields. Naquadah reacts violently with potassium, resulting in massive explosions with radioactive potential.
As a material Naquadah is the greatest material one can use to construct something, this is why both Spaceships as Stargate's use large quantities of refined Naquadah in their construction. The Asgard constructed a mothership named the O'Neill out of a Naquadah-Trinium-Carbon alloy which became the most durable and impressive design in the galaxy. The Ancients set up gates, and bases on Naquadah rich planets, explaining how the Goa'uld gained access to such an incredibly rare element.
Naquadah is also the greatest energy amplifier in existence it is used to make Naquadah reactor's to create normal energy and Naquadah fusion-reactors which create enough power the operate Spaceships and Hyperspace Drives and even Miniature Fusion Reactor which provide the massive amounts of energy Stargate's need to create a stable wormhole. The Goa'uld also used Liquid Naquadah to power their Staff Weapons and normal Naquadah to make Naquadah bombs even the Sarcophagus ran on Naquadah Amplified Energy.
Goa'uld symbiotes have even adapted to have Naquadah in their blood stream which allows them to use the most vital of Goa'uld technology, including the controls of a mothership, and both the Kara'kesh and the Jovak'sul. Because of this Goa'uld can even detect the presence of Naquadah within a host body. Hathor and Setesh both detected that Captain Samantha Carter had been taken as a host and Hathor could even detect the Stargate itself even though it was buried beneath Cheyenne Mountain.
Many smugglers as well as the Lucian Alliance use Naquadah as currency. With refined naquadah being worth more the unrefinded naquadah and liquid naquadah being worth more then Weapon-Grade Naquadah which is worth way more then refined naquadah.
Crystal Technology of various kinds is also based on the use of an Naquadah allotrope.
Naquadah is quite malleable and can even be easily beaten enough to become transparent it is more dense then Gold.
Mining Naquadah is a very hard labor intensive job, not a lot of people would not willing do this job, that is why both the Goa'uld and the Lucian Alliance have used slave labor in order to mine Naquadah while the Tau'ri have recently started using prison laborers in order to mine it. Since Naquadah is very rare planets with large deposits of Naquadah like Abydos are in very high demand.
Most Naquadah is mined by hard rock mining with only some of it being placer mining. Jaffa are the only ones suited for purify Naquadah and creating refined naquadah for since they were the only ones strong enough to stand the intense heat and toxic gases of the refining process.
Naquadah does not react with oxygen at any temperature; similarly, it does not react with ozone. It is unaffected by most acids and bases despite this it is a very workable element.