Naqahdah (also spelled "Naquahdah" or "Naquadah") is a fictional, superheavy metal used in Stargate SG-1. It is also in the original ''Stargate'' movie, though never named, only described as a quartzite-like material; it was not stated why it was quartzite-like, but fans speculate that it turns physical impacts against it into electricity, the so called piezoelectric effect. It has a dull grey sheen in its natural form, and glows green in a liquid form.

A variant spelling of the name, "naquahdah", is sometimes seen in various sources (including the official sites) but the "u" is not present in the instances where the word is spelled on-screen. The name originates from the Egyptian village Naqada.


Naqahdah is the basis for all Goa'uld technology, and the material is used to handle the massive energy requirements in order to create a stable wormhole by a device known as a Stargate, which is composed almost entirely of Naqahdah.

At least 4 variants exist: Liquid Naqahdah, used to power staff weapons, Heavy Liquid Naqahdah (mentioned in a dream sequence , leaving its existence in true Stargate canon questionable); and Naqahdria, which is an unstable heavy Naqahdah isotope. The Goa'uld have many mining operations on various planets extracting the mineral to be refined into Weapons-Grade Naqahdah, which is even more rare than the raw ore and is considerably more dense. Weapons-Grade Naqahdah is so dense, in fact, that it generally requires two Jaffa to carry a small brick of it.

Naqahdah is very rare, and does not exist naturally in Earth's solar system. At least some of Earth's naqahdah supply comes from P3X-403, where, as a result of a treaty negotiated by Daniel Jackson with the native Unas, the Unas work the mines and turn over the naqahdah to the SGC. The Unas agreed to do this both to prevent the humans from desecrating Unas holy sites while mining it themselves and to facilitate the SGC's war against the Goa'uld, whom the Unas hate.

Technologically, naqahdah is very important for most advanced races. As the only known material to interact with neutrinos, which are used to energize the material, and a superconductor capable of storing and converting many types of energy, including electrical and thermal forms, naqahdah is important in high-energy applications such as weapons, propulsion mechanisms (including hyperdrives) and force-field technologies. The refined weapons-grade metal has been shown to amplify the effects of both standard chemical and nuclear explosions, exploited by the System Lord Ra to create an enhanced nuclear warhead which was ultimately used against him. This effect has also been used by Earth forces to produce enhanced warheads and bombs, including a 'gate-buster' capable of producing a multi-gigaton blast. Naquadah itself can be used as an explosive; compact reactors utilising its energy-production properties can be set to overload, producing an uncontrollable chain reaction. The use of naquadah as an energy source appears akin to standard nuclear fission reactors, although the radiation generated appears to be far more limited, shown by the lack of shielding used on naqahdah generators. Naquadah has also been seen to react violently with potassium. The mechanism of this reaction is unknown, but not believed to be entirely chemical, evidenced by radiation release. The Goa'uld used this property to create a bomb implanted within a living person in order to destroy the Earth Stargate.

Naqahdah is also an integral part of the Goa'uld's physiology, giving them the ability to use their technology, and to sense the presence of other Goa'uld within a close range, which also holds true with Tok'ra and Jaffa. The host of a Goa'uld symbiote carries naqahdah in his or her blood which remains in their system, even if the symbiote is removed, the only exceptions being artificially cloned symbiotes and the Goa'uld who remained on their native homeworld (known only by its SGC designation, P3X-888), found to have no naqahdah. To explain this inconsistency, it is believed that heavy use of naqahdah-based technology, such as the sarcophagus, may have introduced the metal into their systems centuries after they left P3X-888.

Naqahdah is apparently also the standard medium of exchange within the area that is or has been under the dominion of the Goa'uld; weapons-grade naqahdah is preferred by the traders of the Lucian Alliance.