Glass Weapon

If you think the sword is dangerous, just wait until you see his cannons.

"He uses glass knives. Chips them out of plate glass. It's the sharpest blade in the universe, you know."

— Chuck Wrightson on Raven, Snow Crash

In fiction, we all know that anything can be a weapon. What's also true is that a weapon can be made of anything, including glass, something known more for its fragility than anything else.

This isn't quite as improbable as it initially seems; before metalworking, glass was one of the most popular materials for making weapons with sharp edges, along with flint and obsidian (volcanic glass). Even today, glass knives are used in incredibly precise operations, since glass edges don't degrade as quickly as metal does, and it can be sharpened so much that it can create real-life examples of Absurdly Sharp Blade.

However, that doesn't get around the unmistakable fact that glass is incredibly brittle. It's one thing to use it as the head of an arrow or spear, but anything like a sword or dagger that's meant to block as well as attack would leave the wielder with a shattered weapon before long.

Not so in fiction, though! In fiction, anything from solid-glass swords to outright hammers made of glass are possible, often with the Hand Wave of magic, which is why it's not uncommon for them to have magical properties themselves. These items still tend to be frailer than the regular versions, but nowhere near as fragile as they would realistically be.

An advantage that is sometimes claimed for glass weapons is that they can be hidden by immersing them in water. This would not work as well in real life, as water and glass have an index of refraction of 1.33 and 1.5 respectively. Corn syrup would be a better refractive match, but also kind of messy.

Grievous Bottley Harm is an improvised version, where a glass bottle is used as a weapon. Contrast Soft Glass, where glass is much less injurious than it should be, and compare Crystal Weapon for another type of brittle material unrealistically used for weaponry. Also (despite being its Trope Namer) not to be confused with Glass Cannon, which is a term for anything with high offensive power but very little defense (although, it is named for what would be an example). Still, compare The Power of Glass.

If the glass weapon is really just a glass shard fashioned into some kind of crude knife or stabbing and slashing weapon, then that's a Sinister Shiv.

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Examples:

Comic Books

• The Swords Of Glass is a French comic about four magical swords made of glass. Besides their obvious cutting ability, they can also turn people to glass.

Film — Animated

• Shrek the Third: When the princesses are gearing up to rescue Shrek from Charming's clutches, Cinderella is shown sharpening her glass slipper on a grinding stone. She later uses it like a boomerang to take out some guards.

Film — Live Action

• Daredevil (2003): During a fight between Daredevil and Bullseye in a Catholic church, Bullseye picks up the shards of a shattered stained-glass window and hurls them at Daredevil like throwing stars.
• Moonraker: James Bond's battle with Chang in Venice mostly happens in a museum of glass art. They end up trashing the place and using the various centuries-old art pieces as weapons. Bond manages to chop Chang's wooden kendo sword in half with a glass-handled rapier.
• Sherlock Holmes (2009): Lord Blackwood attempts to stab Watson with a Blade Below the Shoulder made of glass in the opening scene of the movie. He's saved from an Eye Scream only because Holmes is, of course, paying attention to his surroundings.
• Stardust: When setting out to hunt down a fallen star and remove her heart, the witch Lamia brings a glass knife to do the task (which later shatters as the star escapes her clutches).

Literature

• Akata Witch: Sunny's juju knife has a blade of paper-thin green glass. Justified in that it's a conduit for her power, which makes its physical composition more or less irrelevant, but even other magical people think the blade is strange.
• In one of the Bony detective novels by Arthur Upfield, the victims are killed with coloured glass daggers that were once used as props in a magic act to which characters are connected.
• Spider Robinson's Callahan's Crosstime Saloon short story "The Law of Conservation of Pain". One of the guest characters has a futuristic gun made of glass. Jake Stonebender shatters it by playing a high frequency note on his guitar.
• There's a John Dickson Carr story where a killer hides a glass knife by dropping it into a jug of water.
• The first-person narrator of Death's Head mentions small glass knives early in the second book. They can be bought by the dozen and the user can easily break the handle off after stabbing, making the blade hard to dislodge. The narrator contrasts them with his opponent's enormous knife, the mark of a guy who takes pleasure in killing painfully (whereas he, as a soldier, kills efficiently instead).
• In the Eighth Doctor Adventures novel Demontage an assassin is disguised as a wine-glass salesman, and his Scaramanga Special (comprising two knives, a single shot gun and a set of lockpicks) is therefore made of glass.
• In the sci-fi short story by Comte de Villiers de l'Isle-Adam, "L'Etna chez soi", there are very detailed descriptions of glass arrows loaded with chemicals that then explode on impact.
• A unique example in Gaunt's Ghosts actually takes advantage of the properties of glass. Security personnel on an Imperial vessel have shotguns loaded with glass flechette shells as they don't want any risk of puncturing through the hull and exposing everyone on board to the vacuum of space.
• Mercy Thompson: In River Marked, the River Devil can only be killed by cutting her heart out with a set of obsidian knives, as she's magically resistant to metal blades; Mercy is sent out with a set of twelve, as even obsidian edges will eventually dull against the River Devil's flesh. Turns out an ancient fae walking stick will also do in a pinch.
• In Mistborn: The Original Trilogy, glass knives are commonly used against Mistings and Mistborns as they can detect and control metal items. The State Sec's dreaded Steel Inquisitors often use obsidian axes for the same reason.
• Modern Faerie Tales: The faerie-made glass sword in Valiant. When Val is stopped by a police officer for carrying it on the subway, she manages to convince them that it's ornamental by unwrapping it a bit to show that it's made of glass.
• The Obsidian & Blood series by Aliette de Bodard, being an Urban Fantasy series set in the pre-Columbian Aztec Empire, frequently features obsidian weapons.
• In Snow Crash, the Big Bad Raven uses glass knives that are Sharpened to a Single Atom because they're undetectable by security systems and can cut straight through bullet-proof vests. He also uses glass-tipped harpoons.
• In The Stepsister Scheme by Jim C. Hines, Danielle's glass sword contains her mother's soul.
• Tarzan the Terrible: Having escaped from the city of A-lur, Jane Clayton finds shelter by a small jungle stream. While bathing in the stream, she discovers that the stream bed is paved with small rocks, including many sharp-edged pieces of obsidian.
  Jane Clayton was elated. Here, God-given to her hands, was the first beginning with which she might eventually arrive at both weapons and tools—a cutting edge. Everything was possible to him who possessed it—nothing without.
• In Larry Niven's short story "What Good Is a Glass Dagger?", it turns out that a glass dagger has one significant advantage: it can be hidden in water.
• The Wheel of Time: Callandor, the page image, actually isn't this, but a Crystal Weapon - however, it's a very easy mistake to make, and everyone assumes that it is made of glass.
• Worm: Shatterbird can control all glass in a large area with her voice, so attacking with glass shards actually makes sense for her. If one breaks, that just means she now has two shards with freshly sharpened edges.

Live-Action TV

• Downton Abbey: The concept is critiqued and lampshaded by the Dowager Countess of Grantham: Since they possess large estates which require a lot of hands to keep things running, she sees it as the duty of the upper classes to provide employment to those in need, which causes positive ripple effects for the community.
  "An aristocrat with no servants is as much use to the county as a glass hammer."
• Game of Thrones: The White Walkers can be killed by weapons made of dragonglass (i.e. obsidian, a volcanic rock with glass-like structure).

Tabletop Games

• Dungeons & Dragons:
  • Glass weapons can be considerably more practical in D&D. The 8^th level "Glassteel" spell can permanently make a glass weapon as tough and strong as steel.
  • In Dark Sun, metals are scarce, so obsidian is a typical material for cutting and piercing weapons.
  • In the 5th Edition module Lost Mine of Phandelver, the rogue wizard known as Glasstaff wields, naturally, a Magic Staff of hollow glass, enchanted to be as hard as oak and to carry spells of shielding.
• In Changeling: The Lost, fetches can learn to pull a glass blade out of any pane of glass they can touch, with mirrors giving the best result.
• In Magic: The Gathering, a literal Shard of Broken Glass is a piece of equipment creatures can equip themselves with.
• In Warhammer Fantasy Roleplay, the Mayincatec-themed Lizard Folk wield weapons of Obsinite volcanic glass. Unlike real-world obsidian, it's nearly unbreakable and capable of shattering armour; the secret of crafting it is closely guarded by their artisan-priests.

Video Games

• In Battle Realms, the swordsman unit can be equipped with a battle gear upgrade called "Glass Sword", which could instantly kill another unit, but also sacrifice the swordsman in the process.
• In The Binding of Isaac: Afterbirth, you can create the Glass Cannon, which is exactly what it sounds like, in every sense. It's incredibly powerful, but lowers your health to just 1/2 heart, meaning that you'll be killed in a single blow if something hits you. Repentance removed the health downgrade, but getting hit while holding Glass Cannon temporarily breaks it, causing damage done to Isaac to be increased by two hearts and causes him to leave behind blood creep until the Glass Cannon is fixed.
• Crypt of the NecroDancer has glass weapons that do very high damage but break if you get hit. There's also glass armour that negates damage but (again) breaks if you get hit and an item called the Glass Jaw that lets you inflict double damage but turns you into a One-Hit-Point Wonder.
• Dark Parables: The Final Cinderella has the Glass Wand, a Magic Wand that's been passed down through generations of Godmothers that can destroy evil and break curses on objects, as well as imbue an object with positive energy. As a very major enemy in the game is a Perverse Puppet, this is a very useful weapon to have.
• Brandon, one of the psychopaths in Dead Rising 2 uses a large shard of broken glass as an Improvised Weapon.
• Divinity: Original Sin II: The legendary glass sword Anathema holds the spirit of a demon and is powerfully magical, but is brittle and can't be repaired like other weapons, so it breaks after it deals a single blow.
• In The Elder Scrolls series, two of the setting's Fantasy Metals are different but related forms of volcanic glass.
  • First and most obvious is the rare, milky translucent green volcanic crystal that is normally known simply as "Glass" that is far stronger and has a much higher melting point than the everyday glass found both in-universe and IRL. Deposits can be found all across Tamriel, but mostly occur near volcanoes, with the richest source of glass on the continent being Red Mountain volcano in the Dunmer (Dark Elf) homeland of Morrowind. Glass equipment uses both the eponymous material and rare, lightweight metals in their construction, with the armor being very effective at shock absorption and the weapons being incredibly sharp, but while the glass they're made from is more durable than obsidian it's still brittle enough to suffer more from wear and tear than other materials and need frequent repairs. There are also several differences in the material throughout the games:
    • Morrowind had the most "realistic" take on glass equipment: they were made using an unnamed black metal with glass incorporated into the object, and needed frequent repair due to being relatively brittle and chipping in combat. The weapons were either bladed (swords, knives, axes, and halberds), or piercing (arrows, throwing knives, throwing stars), with the single "blunt" glass weapon being a metal staff with a number of glass spikes on top that would probably make nasty puncture wounds on anyone hit by it. Meanwhile, glass armor is constructed primarily from metal that is studded with glass, with the pauldrons, elbow-guards, and boots incorporating some nasty-looking spikes that could probably be used offensively if the game engine allowed it. An interesting bit of trivia is how people in-game will credit the Altmer (High Elves) of Summerset Isle as the most famous users and creators of glass equipment despite Summerset being on the other side of the continent from Red Mountain, which is located smack dab in the middle of the island the game takes place on. This is because of three major factors that have turned Red Mountain into Tamriel's equivalent of Mordor,^detailsA: it constantly spews massive ash storms carrying incredibly nasty Blight diseases, with the worst being Corprus, an incurable affliction that ravages the body and mind of anyone infected. The mountain's slopes are home to both animals and people who have caught these diseases and can easily transmit them to anyone they touch. B: It's the home of Dagoth Ur, a Semi-Divine lunatic who created the aforementioned diseases and has an army of insane cultists and mutated abominations that even the elite, handpicked warriors of the Buoyant Armigers try to avoid due to said cultists and abominations being all too eager to "gift" people with Corprus. The various Dwemer ruins also contain numerous still-active Animunculi that won't hesitate to slaughter anyone trespassing in their creators' ancient home. C: even without the various supernatural forces infesting the slopes, Red Mountain is still dangerous at the best of times due to the fact that it's still an active volcano. which means that even in Morrowind glass equipment is rare enough that only the elite warriors of the Tribunal Temple or the very rich can ever expect to get their hands on it. On a final note, "raw" glass (the ore) could also be used in alchemy.
    • In Oblivion, glass equipment now included maces, hammers, and bows for some reason (though the bows consist mostly of wood with metal and glass studs near the grip). The armor seems to be made almost entirely of glass, with chain-mail protecting the joints and waist (and in the case of the female armor set, the midriff), but otherwise incorporating relatively little metal into the construction.
    • In Skyrim, glass' relatively brittle nature no longer has any bearing on gameplay since equipment no longer degrades with use. Strangely enough, the developers chose to make glass equipment something created using malachite and moonstone (neither of which should be confused with real-life malachite or moonstone), which is just as confusing as their decision to make steel equipment require corundum to make. Since moonstone is also used to forge Elven equipment, which glass equipment bears a distinct resemblance to, we can presume that the weapons and armor in Skyrim are made in the Altmer style.
  • The second type is called "Ebony", an extremely hard and durable, glass-like substance (the mention of "folding" when smithing it lends evidence that it may be some manner of metallic glass) that has nothing in common with the real-life wood of the same name aside from its black coloration and considerable weight, traits which are also found in obsidian. Legends say that it's the crystallized blood of Lorkhan and/or other gods; this being The Elder Scrolls, neither explanation is mutually exclusive and both have an equal chance of being true. Whatever its true nature may be, ebony is an extremely rare and valuable substance that can only be found in Morrowind or the regions surrounding it, with the richest deposits being found on or near Red Mountain and even more difficult to mine than glass since ebony is harder to extract from the surrounding rock. A smith who knows how to properly work it is just as rare as the substance itself, but ebony armor and weapons are of a quality only surpassed by some legendary artifacts and Daedric equipment, with the latter requiring ebony to create. The weapons, in particular, lack the brittle nature of their glass equivalents and don't require nearly as much effort to repair. Finally, it also had alchemical properties in ''Morrowind' that have not appeared in later games.
• Endless Legend features the early-game Fantasy Metal "glassteel", a lightweight greenish-golden metal that forms vine-like fronds in the earth. Equipment made of glassteel filaments dramatically improves the initiative of units, in contrast to its counterpart titanium which focuses on defence and attack power. Notably, rather than solid glass, glassteel weapons are portrayed as being mostly constructed of wood, with the valuable metal used to add cutting edges and decoration.
• Enter the Gungeon:
  • One of the many, many guns that can be acquired is a literal Glass Cannon, which, true to its form, is capable of dealing a lot of damage to its targets, but breaks if the wielder takes a hit. Of course, 'breaking' in this context just results in its remaining ammo being lost, so, if you can find an ammo pickup from there...
  • It's also possible to acquire a glass shield, in the form of a Glass Guon Stone. When you pick one up, it orbits you and blocks enemy projectiles, and stacks with any other Guon Stones (Glass or otherwise) you may have acquired. If you get hit, however, any Glass Guon Stones you had on your person break.
• Fable has obsidian weapons, which are a notch up from steel in the Elemental Crafting ranks but which act like metal in every respect. Flavour text also says that they have an unsettling appearance, a pervasive chill, and a reputation for being used in evil deeds, although this has no effect on their in-game use.
• The Final Fantasy Legend and Final Fantasy Legend II include the glass sword, an incredibly powerful weapon which breaks after a single use.
• Fire Emblem: The Nintendo DS remake of Fire Emblem: Mystery of the Emblem introduces a subset of weapons made out of glass. They are as strong as the fairly powerful Silver weapons while also not requiring a high weapon rank to use (all but the Glass Staff, which requires a D rank, can be used at E rank, the lowest weapon level). However, this is offset by the fact that they have an abysmal durability; one weapon has only three uses before breaking. Fire Emblem: Awakening brings most of the weapons (with the exception of the Glass Staff) back, where they work the same way.
• For the King has a class of glass weapons in three tiers: swords, rods, bows, and lutes can all be found in glass, sapphire (apparently not a crystal), and obsidian. It isn't explained how, for example, one could draw a glass bow, but as a small nod to physics, these weapons shatter on a failed attack.
• Mass Effect 3: Omni-blades are silicon carbide (glass mixed with metal and carbon) blades flash-forged by an omni-tool and suspended in a force field above the wielder's wrist. When it shatters the wielder just prints off a new one.
• The Minecraft mod The Twilight Forest includes the Glass Sword, a rare weapon which deals absurdly high damage but breaks after a single attack.
• Rise of Legends has the Glass Cannon unit, which is a cannon made of glass. As it lacks much offensive power (and is, if anything, rather sturdy for an artillery piece), it doesn't, qualify to be a Glass Cannon as in the trope.
• In RuneScape, an obsidian sword, knife, and mace are found and used to unlock a door in one of the quests. They aren't, however, used to fight.
• Sunless Skies has "The Tears of Astolat", a somewhat unique weapon created by exposing a regular train-mounted autocannon to the hateful, vitrifying radiations of the Clockwork Sun (and the rest of the train, crew and all; it wasn't exactly made on purpose). It's very fragile, so salvaging it is difficult, but bullets come in, ultra-sharp glass fletchettes come out. In gameplay terms, it's a Tier 2 weapon: much better than your starting Tier 0 weapon, and better than a Tier 1 weapon, but requiring significant stats to actually use it properly.
  Description: "The mirror crack'd from side to side." A relentless chain gun that fires shards of vitrified ammunition at a rapid clip. Ensure that the last thing your enemy sees is their own screaming face, reflected in the glass.
• Tibia has an obsidian lance as a dropped weapon, and in a quest it can be combined with steel to create an obsidian knife.
• The Ultima series had glass swords from Ultima V onward: one-hit-one-kill weapons for practically every enemy in the games that shatter beyond repair upon a single use.
• A Very Long Rope to the Top of the Sky: There's the Glass Sword, whose Flavor Text is: "While not physically strong, the glass allows it to more easily channel magic."
• Warframe has Gara, whose powers all revolve around glass, either using it to kill or protect. Her update also introduced the Volnus (a bladed hammer made of a glass-like material), the Fusilai (throwing knives made of glass) and the Astilla (a shotgun that fires glass slugs). Later updates added a villain known as the Glassmaker, also known as Nihil, an Orokin Judge / Executioner, who killed perceived criminals by entombing them in molten glass using an ornate glass greatsword known as Vitrica, which becomes usable by the player after his defeat. Said process also traps the target's soul and partially transforms it into a Cephalon, a fate that befalls the Glassmaker himself when he has his self-uploaded soul trapped in an oubliette.

Web Animation

• RWBY villainess Cinder Fall has a Semblance called "Scorching Caress", which lets her superheat and reshape matter. She can use this power to turn basic earth or Dust into weapons made of obsidian, black volcanic glass.

Web Comics

• Felicia, Sorceress of Katara: The Champion of Katara wields a legendary crystal sword, it's magic, though most enemies stop fighting when it's drawn.

Web Videos

• Critical Role: Campaign Three:
  • Ashton Greymoore the barbarian wields an oversized warhammer with a glass head, fitting with the stone skin and crystal hair they have as an Earth Genasi. When Ashton suffered a major head wound, their artificer friend patched it with glass and made the hammer with the leftovers, enchanting it to be unbreakable.
  • Crafters on the metal-poor moon Ruidus make weapons out of a natural glass that's mined there — such weapons are prone to break but have a much greater Critical Hit chance and can synergize with the wielder's Psychic Powers.

Real Life

• The Aztec maquahuitl was a length of wood with shards of obsidian, volcanic glass, embedded into the edges. Reports claim that it could decapitate a horse. They also frequently used obsidian to make knives and arrowheads, including sacrificial daggers.
• In a Real Life inversion, some scalpels are made from obsidian, especially for extremely delicate surgeries on parts like the eyes and brain. They're said to be sharp enough that they can be used without anesthetic. They're not all that commonly used, however, due to their unfortunate tendency to leave behind tiny, wickedly-sharp fragments. Ouch.
• Weapons made out of glass aren't unheard of either, especially in the modern day. However, these are intended more as art pieces rather than actual weapons. Sometimes, they may not even carry an edge specifically because they could cause some damage.

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