Orichalcum

Orichalcum is a legendary precious metal that was mentioned in Plato as used in Atlantis. (Orichalcum appears many other places in classical Greek and Roman writings—the Homeric Hymns assign gold and orichalcum ornaments to Aphrodite -- but it's the Atlantis reference that it's remembered for.) It has since been commonly used in fantasy literature and games as a type of Unobtainium. The term is Greek for "golden stone" and originally meant "mountain copper" or "mountain metal," though nobody is sure exactly what it was supposed to be. Possibilities range from an alloy of normal metals to a completely fantastic material, though the most common perception is that it is brass.

For some reason, translators often fail to recognize the word in media of Japanese origin, leading to misspellings like "orihalcon".

Compare Mithril, Adamantium, Thunderbolt Iron. Subtrope of Unobtainium and/or Green Rocks.

Anime and Manga

 * In Slayers, as "Orihalcon". It has turned up in both the anime and manga, misspelled the same....
 * In this series, orihalcum's schtick is magic resistance. The metal can block any spells.
 * In Nadia: The Secret of Blue Water Nadia's pendant is eventually revealed to be made of orichalcum (and associated with Atlantis).
 * Used in Yu-Gi-Oh! in association with Atlantis., as "the Orichalcos". The members of DOMA/DOOM all had rings with bits of Orichalcum in them, and they are the only way to break the Seal of Orichalcos (if you lose a duel inside the seal, your soul gets eaten by the Leviathan.
 * Well, hitting it really hard with a Millenuim Item works too...for a given definition of "works".
 * Yu-Gi-Oh! GX has an unrelated character with an "Eye of Orichalcum" embedded in his face.
 * Transformers Armada has the Mini-Cons from a sunken city called the Orichalcum (translated as "Olihalicons").
 * The warriors of Athena and the knights of Poseidon in Saint Seiya wear orichalcum armor.
 * The orihalcon dagger of Natsuki in Hyper Police (translated as "oriharucon").
 * In Black Cat the Chronos Guardians use weapons made of orichalcum.
 * "Orihalcon" is sought by the Atlanteans in "The White Whale Of Mu.
 * The weapons and body armor used by Yu Ominae, the US Army's Machineer's Platoon and the Trident Corporation in Spriggan are made of "orihalcon" or "omihalcon".

Comics

 * Orichalcum is retrieved from Atlantis in the opening scene of Iron Man Noir, in which it's a MacGuffin power source.

Film -- Animation

 * The Mother Crystal/Heart of Atlantis from Disney's Atlantis: The Lost Empire is actually implied to be made of Orichalcum.

Literature

 * A metal used by the Atlanteans in E. Nesbit's The Story of the Amulet.
 * In Decipher by Stel Pavlou, also used in association with Atlantis.
 * In the Pendragon Cycle it is a substance used in Atlantis.
 * Appears in Dinotopia as a substance used in a piece of a key, first thought to be bronze.
 * In John C. Wright's The Golden Transcedence, taking place in the Golden Oecumene, a projected future includes more Oecumenes, about other star systems. One is the Orichalcum Oecumene.
 * Discovered by, of all people, Biggles (who then loses it again in a landslide) in a short story from the (perfectly canon, surprisingly) book "Biggles, Charter Pilot".
 * Subtly name-dropped in the Ciaphas Cain series, where the company is deployed to a planet called Simia Orihalcos... yep, "Brass Monkey".

Live Action TV

 * In Go Go Sentai Boukenger one treasure from Atlantis is first thought to be made of orichalcum. This treasure turns out to be the Vril, an artifact that gathers information from nearby objects to duplicate them in order to eventually replace the human race.

Tabletop RPG

 * In Exalted, Orichalcum is a magical metal associated with the Solar Exalted. The manufacturing process involves smelting gold in the heart of a volcano while using an elaborate array of mirrors to shine distilled sunlight on the metal (why? Because it's Exalted).
 * Orichalcum appears in Shadowrun. It's a very rare metal, known for reacting and conducting magic. It is used to create various magical foci, especially weapon focus. It has also appeared in the Shadowrun video games.
 * Also appears in Earthdawn, where it's the result of fusing the five True Elements.
 * Appears in Mage: The Awakening, where it is also called "perfected gold".
 * The Nephilim RPG has "orichalka" as a material from Saturn, used in the fight against the Nephilim in Atlantis.
 * Arduin Grimoire has a spell "Gandolyn's Gates", a spell which traps a person in a tower of orichalcum.
 * In the D20 (?) book Advanced Gamemaster's Guide from Green Ronin, it is a material to make weapons and armor.
 * Mutants and Masterminds from the same company, has it as a golden metal from Atlantis, whose secret is lost.
 * Used in the Immortals Handbook - EPIC BESTIARY: Volume One by Eternity Publishing.
 * In 4th Edition Dungeons & Dragons, there is a type of metallic dragon called an Orichalcum (or Orium) Dragon obsessed with finding the secrets and reviving the glories of past civilizations.
 * Orichalcum in GURPS looks just like bronze but it much stronger and automatically makes blades forged from it extremely sharp.
 * It's also a room-temperature superconductor, should anyone come along who knows how to use that sort of thing, as noted in the Infinite Worlds sourcebook.

Video Games

 * Orichalcum is a central plot device and Plot Coupon in Indiana Jones and the Fate of Atlantis, a classic LucasArts Adventure Game which never got made into Indy 4. It's used as fuel for the Atlantean's abandoned ancient artifacts scattered around the globe, which Indy must dig up. The Nazis want it for nuclear power because it.
 * Appears as an Item Crafting material in the Star Ocean series. In the first two games, Orichalcum is a strong metal which can make some very good weapons, armor and accessories. In the third game, finding the right Inventors to produce Orichalcum reliably is the functional in-game equivalent to splitting the atom.
 * Also used in Shining Force III as material the blacksmith can use; it's the best material, beating out Mithril.
 * And in Shining Soul II used to make Ice and Holy elemental equipment at the blacksmith.
 * Romancing SaGa 3 the dolphin statue in Vanguard is made of it; in enhances water magic which allows the city to move freely in the ocean.
 * A type of pin used for trading in The World Ends With You.
 * Also appears in Golden Sun: The Lost Age and Golden Sun: Dark Dawn, as an Item Crafting material called Orihalcon (that also Randomly Drops), used for getting one of the game's Infinity Plus One Swords. Strangely enough, you can't find any in Lemuria, the game's Atlantis equivalent.
 * Appears in the Final Fantasy series as items made of the material, with various spellings. An orichalcum knife is a very strong item.
 * The MMORPG Final Fantasy XI has it available in the form of ore to make items.
 * Also in Final Fantasy Crystal Chronicles.
 * Shows up in a couple of the Kingdom Hearts games as an Item Crafting material. Kingdom Hearts II even has a stronger variety called "Orichalcum+" that is needed to make the Ultima Weapon.
 * Used to create jewelry in some of the Harvest Moon games.
 * Also appears as a rather worthless item in Harvest Moon DS.
 * Appears in the MMORPG Maple Story.
 * Of note, it is called 'Orichalcon' in-game because Orichalcum has the syllable 'cum' in it, which is censored out.
 * And in Legend of Mana.
 * And Flyff, which calls it "Shining Oricalkum."
 * Appears in Kirby Super Star as the treasure "orihalcon".
 * In Master of Atlantis - Poseidon as "orichalc". It is used as a monument decoration, as well as fuel for the deadly Atlantean fire.
 * "Orichalkos" is all over the Atlantean civilization of the Age of Mythology expansion pack, "The Titans". It is used to explain some of their more advanced technology (like the Fire Siphon), a common mentioned material of advanced upgrades and the strongest material the Atlanteans can make their walls. The metal is also mentioned to magically become very lightweight after being quenched in seawater.
 * Tactics Ogre has it in the form of a sword translated as "Oricon". Also as "Oracion" in Knight of Lodis.
 * The Orichalcum is Sophititia's legendary weapon in Soul Calibur II and can be purchased in Soul Calibur III.
 * The Sword of Kings in Dragon Quest III is made of the metal "Oricon".
 * It is also used for Dai's sword in Dai no Daibouken.
 * It is also an Item Crafting material in Dragon Quest VIII.
 * The near-unbreakable shield in Dragon Quest Swords is a SPOON made of Orichalcum, but due to its obviously small size which can't be increases and that if you can block as accurately with any other shield as you can with the spoon, they'll be just as durable, it's not nearly as useful as it'd initially seem.
 * It makes a comeback in Dragon Quest IX as one of the greatest, yet rarest alchemy ingredients. To give you a scope on how rare it is, every other mineral in the game can be found as Randomly Drops or by finding them on the ground in certain spots of the world map. Orichalcum is found NOWHERE in the world and the only monsters that drop them do so with a 1/256 chance, which is as rare as it gets in this game. Fortunately, when you do get your hands on some, you can use it for some of the best gear in the game, such as the Sage's Stone, which heals your entire party, as well as Erdrick's gear, which is the best gear in the game barring the Uber-gear.
 * In Dragon Quest Heroes: Rocket Slime, both orichalcum and orichalslime are used as weapons and alchemy ingredients.
 * The general rule of thumb in Dragon Quest is that if it's made of Orichalcum, it either kicks three different kinds of ass or is a flat-out Game Breaker.
 * Used as a power source in Devil May Cry III.
 * The MMORPG Ragnarok Online used "Oridecon" as a crafting material.
 * The Grim Angels in Dept. Heaven use weapons made of this material.
 * City of Heroes and City of Villains have it as salvage.
 * Tech Romancer has a mecha, G-Kaiser, made of the material "Orihalconium".
 * The Elder Scrolls has a tower made of "orichalc", which was on a sunken continent named Yokuda.
 * As of the fifth game in the series, orichalcum is used to make Orcish armor and weapons, which in previous installments was just high quality steel equipment.
 * Super Robot Wars has a number of mecha and weapons made of "Orichalconium" (most famously Cybuster) or the stronger "Zol-Orichalconium" alloy ("Z.O." for short). In the Original Generation games, it plays the same role as Alloy Z and Super-Alloy Z.
 * Used for Item Crafting in Valkyrie Profile.
 * Used for both the main character's weapon and the bosses' weapons in Eve of Extinction. Hilariously awkwardly pronounced in-game as "OriKILLUM" and "oRICKulum."
 * Available by Video Game Stealing in Castlevania: Curse of Darkness as an ore used to forge powerful items.
 * Used for dwarven crafting in Lineage II.
 * A more powerful substitute for bronze in Titan Quest.
 * Tibia has a magic item called the Orichalcum Pearl.
 * Blob Wars has a quest to collect 25 boxes of orichalcum beads.
 * Endless Ocean: Blue World-The orichalcum ingot is one of the legendary treasures, and is the most expensive non-treasure chest salvageable item (and the fourth most expensive overall).
 * Orichalkos, the arcana of metal (and a huge frickin' dragon) from Arcana Heart is clearly named for this.
 * Orichalcum is used to craft either Seth or Kaim's Ultimate Weapon in Lost Odyssey.
 * Appears as a crafting material in Dragon Age II.
 * Appears as a crafting material in the MMO RIFT:Planes Of Telara.
 * The in Kid Icarus: Uprising is stated to be made of orichalcum.

Web Comics

 * Appears here in Mind Mistress.
 * In Irregular Webcomic in the Cliffhangers storyline, starting here.
 * Used in OMFG to parody Black Cat.

Web Original

 * Used in The Descendants. It's first seen as a rough type of armor called 'orihalcite' that even Alloy couldn't effect with his powers. Later appears in a refined form with the proper name.
 * Used with WILDLY variable spelling in the Whateley Universe.