Gem Heart

Behold The Heartcore! The mightiest organ of the demons! Tastes like Dragon Fruit!

There are plenty of reasons to hunt a monster. Maybe you want revenge for the village it burnt down. Maybe you're after the fame and fortune that such a kill can bring.

For those who live in some universes, however, there's another reason: If you cut open its body, you can find a ruby as big as your fist (or even bigger) nestled in among its squishy bits. This is a Gem Heart.

The creature the Gem Heart is in is always large and dangerous; dragons are a common case. Sometimes, the stone comes naturally shiny and faceted, other times it doesn't. Often, this gemstone possesses some special magical ability.

In more fantastical universes, this gem actually takes the place (and function) of a major internal organ; in other cases, it's simply a crystalline growth with little immediately visible effect on its owner's biology. The heart is the most common, hence the name, but finding gems within the brain isn't uncommon either. In works with a higher degree of biological verisimilitude, these stones are often explained away as gizzard stones, used to help the creature break down its food for digestion.

Subtrope of Gem Tissue. See also Power Crystal. Often a form of Body to Jewel. May overlap with Heart Drive or Immortality Inducer.

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Examples:

Anime & Manga

• Fairy Tail: The sequel reveals that dragon lacrima, extremely rare and valuable Power Crystals that contain Dragon Slayer magic that can be implanted into objects or even humans to use said magic, are in fact dragon hearts processed into a crystalline form.
• GaoGaiGar: Gai Shishioh's cybernetic body is powered by a G-Stone.
• That Time I Got Reincarnated as a Slime: The witch Myulan has an artificial heart formed from magic crystal that was "given" to her by the Demon Lord Clayman when he transformed her from a human to a majin. Said heart is "bugged" to let him spy on her at all times, and he keeps her original heart safe and attuned to it so that he can kill her whenever he wants if she doesn't serve him loyally. When Rimuru decides to free her from Clayman's service, he briefly kills her by removing said bugged heart (which destroys her original heart as well) and replacing it with a new and better crystal heart to resuscitate her.
• The Vision of Escaflowne: Dragons have a magical gemstone at their heart that can then be used to power guymelefs.

Card Games

• Magic: The Gathering: Karn was created with a Phyrexian heartstone, which worked until he gave up his Planeswalker spark to help mend time rifts on Dominaria. When he did, the oil in the heartstone gradually corrupted him. During the Phyrexian takeover of Mirrodin, the Phyrexians attempted to convert him into their new Father of Machines. Ultimately subverted: his heartstone was replaced with Venser's human heart, restoring his Planeswalker spark and cleansing him of the Phyrexian corruption.

Comic Books

• Darkhawk: Darkhawk bears a ruby amulet inside of his chest. At one point, the villain Tombstone tore it out, believing it is valuable. Darkhawk recovered.
• Requiem Vampire Knight: Dragons are killed for the large gemstone that forms naturally in their body.
• Superman: Metallo is called "The Man With The Kryptonite Heart!" since his robotic body is powered by a chunk of kryptonite.
• In XXXenophile: Heart of Stone by Phil Foglio, the MacGuffin is a massive ruby carved from the heart of a monster, which induces lust in anyone who touched it with their bare flesh.

Films — Live-Action

• Sucker Punch: When Babydoll kills the baby dragon, it has rubies in its throat that she strikes together to spark a fire.

Folklore

• Some Greco-Roman and medieval natural histories describe draconite, which had to be removed from a dragon while it still lived (as sites of origin being rumored to include the brain and the heart, this was no simple task). True to the trope, draconites were believed to have magical powers.

Literature

• The Aldabreshin Compass: Natural dragons have a gem that relates to their element for a heart. Unnatural dragons created by wizards will fight very hard against natural dragons because the unnatural seeks to replace the void in its heart with the gem from its natural cousin (and occasionally they will break free of the wizard's control if they can feed on enough gemstones; this is why it is vitally important not to summon a dragon near your treasury). It goes without saying, then, that summoning a dragon is reserved for when things have crossed the Godzilla Threshold.
• Ascendance of a Bookworm: Feystones are the hearts of feybeasts crystallized upon their death. This can also happen to humans who have mana.
• Discworld: Trolls have diamond teeth in order to chew through the stone and gems they eat.
• Dragon Rider: Nettlebrand has a golden casket that acts as his heart. It has no actual value, though.
• Everworld: The dragon Nidhoggr drafts the protagonists to recover some stolen items, then magically replaces their hearts with rubies, which will kill them after six days. David is a little freaked out that he doesn't try to do this to Senna. It turns out, as a witch, Senna's heart is so hard that it would need to be replaced by a diamond. Nidhoggr was just being cheap.
• The Inheritance Cycle: Dragons have a gemlike organ called an Eldunarí. In a twist, though, it has no intrinsic value; it's actually the dragon's emergency Soul Jar — if the stone is regurgitated before death, the dragon's consciousness will become preserved there should they die.
• Michael Moorcock:
  • Corum: When Corum slays the god Arioch, Arioch's heart turns out to be a huge glowing gemstone.
  • The Elric Saga: Nanorion stones, a type of gem, are sometimes found as the hearts of demons. They have the magical power to wake the dead or those in a death-like sleep.
• In Her Name: A genoth is a dinosaur-type alien that has gem eyebrows. They have to be removed very soon after the creature is killed for them to be gems, otherwise they quickly fade and crack, becoming worthless.
• The Hero and the Crown: Played with; the last drop of blood a dragon spills before dying turns into a bloodstone (read: a ruby).
• The Heroes of Olympus has Alcyoneus who has a body made entirely of jewels and precious metals, including having a heart made of diamond.
• Star Wars Expanded Universe: Krayt dragons have valuable "dragon pearls" in their gizzards.
• The Stormlight Archive: Many of Roshar's native fauna have gemhearts, gems like raw rubies, emeralds, and sapphires deep beneath their shells, which gather Stormlight and attract various helpful spren. These gems are absurdly valuable, because the gemstones and their Stormlight are the primary currency among humans, due to the face that they can be used by Soulcasters to transmute materials, such as turning rocks into grain or air into stone.
  • Greatshells such as the chasmfiends use them to decrease their own weight, so that the Square-Cube Law won't kill them. By the time of the story, most of their gemhearts are gathered through the slightly unsporting method of waiting until the greatshell is pupating, then cutting through the stone carapace to get to the gem using Shardblades. The chasmfiends' gemhearts are so valuable and powerful that one can pay an entire Highprince's military operating costs for months, and they typically harvest several per week. In fact, they're so valuable that fighting over them has become the entire strategic focus of the war that dominates the plot of the first two books. They remain relevant in the later books; the larger and more perfect a gemstone, the longer it can hold stormlight, meaning the enormous greatshell gemhearts essentially serve as a high capacity tank for Knights Radiant and Magitek.
  • Skyeels take this a step further, using the same gravity-decreasing spren to float.
  • The Parshendi use the gemhearts to trap spren that enable them to change into various forms. They also have an intense cultural taboo against disturbing the bodies of the dead because ancient humans would cut apart the bodies of dead Parshmen to get at their gemhearts.

Live-Action TV

• Doctor Who: In "Dragonfire", the dragon's treasure turns out to be a large Power Crystal contained within its body. Justified in that the "dragon" is actually a robot built around the crystal to keep it from falling into the wrong hands.
• Once Upon a Time: When ripped out, hearts tend to look more like red glowing heart-shaped stones than actual hearts. You can tell a person's Character Alignment by checking how blackened the heart is, squeeze it for use as a magical Shock Collar, or just crush it and kill the person you took it from. A person without a heart also loses the capacity for most emotions. Whether these hearts have any relation to biological anatomy at all hasn't been explored. Two characters Snow White and Prince Charming, share a heart. It's very sweet, so don't ask.
• Titans (2018): This is played with in the first episode of season two. Raven gets her signature Power Gem when Trigon rips out her heart and crushes it, either revealing that the gem was inside or actually turning it into the gem, the show isn't specific. Since it replaced her heart, she can't actually survive without it.

Tabletop Games

• Ars Magica: Vis, crystallized magic energy, is often found coalesced in the magically potent parts of a beast. While not always strictly a gemstone (as the shape it takes is dictated by the storyguide's discretion and the particulars of any individual mage's magic), it often is. A dragon's heart is worth sixty pawns' worth. (To the uninitatied: it's a goddamn fortune.)
• Spelljammer: Buzzjewels are swarming insects that resemble large (hand-sized) dragonflies, which graze on "interesting" minerals like gemstones and eventually crystallize some sort of a small gem in their bellies, with a mildly poisonous bite to use if the swarm is attacked.
• Tenra Bansho Zero: A quite literal example: the "heart engines" powering the Humongous Mecha of the setting each contain the actual heart of one of the native Oni people, who are widely (and largely incorrectly) considered savage monsters by the local humans. Perhaps needless to say, this little secret is not something the people in the know feel exactly inclined to share with the general populace.
• Warhammer 40,000: After being exiled into the Webway, Aurelia Malys ran into a crystalline entity and defeated it, ripping out its heart and her own and exchanging the two. Now that the crystal heart beats instead of her own, she has minor precognitive abilities and complete immunity to psyker powers, which she uses to plot the downfall of Asdrubael Vect, who caused her exile in the first place.

Video Games

• Avencast: Rise of the Mage: The Demon Lord Morgath has a heart of crystal, despite the rest of his body being organic and tentacular. You expose and destroy it as the final stage of his Sequential Boss fight.
• Code:Realize: Cardia has the horologium in her chest, a gem that is the source of her powers, and can't be removed without killing her.
• Dragon Quest VIII: The party has to go on a Matchmaker Quest on the behalf of the Prince of Argonia, who needs to slay an Argon Lizard and harvest their hearts as a sign of his coming of age and the right to marry Princess Medea of Trodain (who, unknown to him, has been transformed into a white mare due to a curse). Unfortunately, this person happens to be Prince Charmles. Literally, that's his name, and he's the epitome of entitled bastardry and a Royal Brat and Dirty Coward to boot. And to make things worse, after you slay a Great Argon Lizard and do the hard work for him, Prince Charmles buys a larger (and presumably fake) Argon Heart from a shady merchant anyway! Son of a... Luckily, this comes back to bite him in the ass hard, costing him Medea and his undeserved sense of entitlement.
• The Elder Scrolls:
  • In the backstory, the legendary hero of mankind (and racist, psychopathic berserker who may have been a Cyborg from the future) Pelinal Whitestrake had a hole in his chest and a red diamond instead of a heart, symbolizing his connection with the "dead" heartless god Lorkhan. He killed those who spoke of such things to him, though.
  • The Elder Scrolls IV: Oblivion: The enemy mooks within the Shivering Isles DLC are the Knights and Priests of Order. Looting their bodies reveal them to all contain Hearts of Order. Their art assets make them look similar to pieces of quartz or diamond, as opposed to the biological Daedra Hearts found on the bodies of Daedra in service to other Daedric Princes. Unlike most examples, these creatures are not large and dangerous, they are mooks.
• Fabula Nova Crystallis: Final Fantasy: The fal'Cie created by Lindzei and Pulse possess crystal hearts. The first real boss fight in Final Fantasy XIII is identified in the targeting menu as the fal'Cie Anima inside the Pulse Vestige, but in reality is just Anima's crystal heart; the entire Vestige is Anima's body.
• Kingdom Hearts: Hearts are depicted with a crystalline appearance.
• Legend of Mana: There's a race of humans called Jumi who all have some sort of precious gem in their chest. If it gets damaged, they can die.
• Monster Hunter: As the primary method of obtaining exotic crafting materials is carving them out of the steaming carcasses of giant monsters, this is both a present trope and driving motivation in the game. Aside from somewhat mundane materials, such as pelts or bones, some larger monsters outright have some parts identified ingame as stones or gems, believed to contain some of the monster’s power. This a downplayed example as in-universe descriptions of the parts say they’re formed within the body tissues of the monster, effectively making them like high-end kidney stones. In addition to the internal organs, some truly massive or tough beasts can also provide minerals by mining their hard outer carapaces.
• Myst V: End of Ages: Part of the backstory reveals that this is true of the Laki, which appear to be something like otherworldly narwhals. The Laki collect gemstones in their gizzards to help them digest, and (before the cities in their world were destroyed by plague) were hunted almost to extinction in gladiatorial games to harvest them. They survived, but they don't get close enough to for the player to interact with them.
• Pokémon Ruby and Sapphire: Deoxys has a gem on its chest that is actually its brain.
• Stinkoman 20X6: The Final Boss has a set of crystals in its chest as its weak point referred to as the Crystal Heart of Mecha-Trogador.

Webcomics

• Crystal Heart: All humans have gems for hearts, while animals still have fleshy ones. Syn Agents weaponize this, swapping their hearts with special, ancient crystals that give them special powers.
• Heartcore: The titular item, Heartcores, are crystals that can be found in almost any living creature that possesses a heart, harvested by using demonic magic against the being who's heart you want to tear out. It serves as the main food source for demons as well as a mighty powerboost that can make the consumer stronger when eaten. They are incredibly valuable if they come from either humans or beastman, leading to demon being willing to start entire wars and genocides to get their hands on them. They also serve as a demons weakspot, since they all have these instead of hearts and the only way to kill a demon is to either destroy the head or the heartcore.
• Unsounded: The "heart" of a waterwoman is a pearl-like stone inside her rib cage. So long as the pearl is intact and in water, they can regenerate any physical damage, although they experience Death of Personality if their brain is destroyed.

Web Original

• The Crew of the Copper-Colored Cupids: Clockwork Cherubs have a gem for a "heart", whose precise function is unclear (it certainly doesn't pump blood, and considering the Cupids have "positronic brains", it doesn't seem to be a Heart Drive either). Most have quartzes, but a few particularly daring Cupids are noted to have diamond hearts.

Western Animation

• The Dragon Prince: Magma titans are gigantic humanoids made out of rock and lava whose hearts are giant Glowing Gems with powerful magical properties.
• My Little Pony 'n Friends: The two-parter "Crunch the Rockdog, Part 1" and "Crunch the Rockdog, Part 2" features His Elevated Eminence, a sapient mountain peak who rules the Purple Mountains. He possesses the Heartstone, a magical heart-shaped gem that lets him feel positive emotions; the characters end up having to borrow it temporarily and take a piece to give Crunch, the episode's titular antagonist, a heart of his own.
• The Owl House: A diagram from the episode "Eclipse Lake" details the ingredients used to create a Grimwalker and their functions, with a Galdorstone (big, glowing blue gemstones that can amplify magic) listed as "heart & power". Hunter being the only known Grimwalker in existence, thus has a gemstone for a heart.
• Skeleton Warriors: The titular skeleton warriors all possess a "heart stone" in their ribcage. Removing or destroying their heart stone causes them to revert back to being humans and is one of the few ways to truly defeat a skeleton warrior, as they'll just pull themselves back together otherwise.
• Steven Universe: The Gems appear to be multicolored space babes with a magical gemstone somewhere on their bodies. In fact, they are the magical gemstones, and their humanoid forms are Hard Light constructs used to interact with the world. As such, they can regenerate from any damage done to their projected bodies, up to and including full disintegration, whereas damage to their gems is life-threatening.

Real Life

• In a less epic vein, oysters, and the pearls they generate. For a long time this was thought to be caused by grit in the shell, but this has long since been scientifically proven false, the pearl actually forms around parasites and worms inside the oyster, which it forms in order to contain them. There's even one particularly famous pearl with a fish skeleton as its core. The idea that pearls form around sand grains still pops up a lot in media.
• A more tragic example: The value of elephant-tusk ivory and rhinoceros horn (considered an aphrodisiac in some cultures) has led to both creatures being hunted to near-extinction.

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