An artifact formed in the Vortex anomaly. Is activated by the heat of the body. Decide what's worse: radiation or knife wounds, and chose the lesser of the two evils. In any case you can sell the artifact for good profit. - In-game description
The Goldfish increases rupture protection and radiation by 5%, making it not particularly effective, and best sold than used.
The Goldfish can be found up the stairs near the entrance to Lab X-16 in Yantar.
A Goldfish can be found in Army Warehouses, near an abandoned car to the east of the abandoned houses on the far northern part of the map (the ones in which the Deal with the snitch quest takes place).
One Goldfish can be found in the Red Forest, next to the hole in the fence near the first Monolith fighter holding an RPG-7u. Another one can be found close to the south-western map border in the deep forest, near the Battery.
It is also contained in two stashes: a stash in Army Warehouses and inside a backpack in Yantar.
The result of a superinteraction of gravitational fields, Goldfish produces its own strong directed gravitational field and significantly increases stalkers' load carrying abilities, which explains why it's always in great demand. Emits radiation. - In-game description
The Goldfish in S.T.A.L.K.E.R.: Clear Sky increases weight capacity by a very large +30kg, allowing the player to carry a lot more gear, while being only a radiation +3 artifact.
The Goldfish is one of the rarest artifacts in the Zone and it only forms in strong gravitational anomaly clusters. The only place the player is likely to find one is the large anomaly cluster near the Devilish camp in the Red Forest. Additionally, one may be found amidst the gravitational anomalies on the hillside west of the military base in the Army Warehouses.
The result of an interaction between a large number of gravitational fields, Goldfish produces its own powerful internally directed gravitational field, which renders items within its range almost weightless. This artifact is most effective for reducing carried weight, which explains why it is always in great demand. Emits Radiation. - In-game description
The Goldfish returns in S.T.A.L.K.E.R.: Call of Pripyat, although its weight effect was largely reduced to +12kg, which still makes the Goldfish a very effective artifact. Strangely, the Goldfish is, like the Gravi, a radiation +3 artifact, making the Wrenched sufficient to counter the radiation effect.
The Goldfish may be found in gravitational anomalies; the PripyatSchool spawns one by default.
If the player has chosen the peaceful way to complete the Hostage crisis, they are given a Goldfish to use as a ransom to get Mitay freed. The player can keep the artifact, although it'll force the player to either pay 15000 RU, give the bandits a Flame, Firefly or Snowflake instead, or kill the bandits to rescue Mitay. If the player has given Shishak the artifact, they can kill him to reclaim it afterwards.