Mysterious Minerals

Bored of giving your players treasure made out of gold, diamonds, rubies, etc? Here are some more obscure minerals and gems with suggestions for how they might be worked into treasures.

 Azurite:
1. Perfect blue discs used as lip-plates by subterranean cultures
2. powder ground up and used as eyeshadow, kept in gold snuff box
3. blue moss-like crystals grown around a skull before the skull is dissolved away, leaving only the brittle blue cast
4. blue disc set into brass plate. Look closely at the blue and you will see a map of the stars

Cerussite:
1. Lattice trimmed by immortal topiarists into a perfect Sierpinski triangle
2. Miniature crystal tree with carved obsidian rooks
3. Crystal 'feather' forms the end of an ornamental quill

 Cornetite:
1. Bulky ceremonial epaulettes with blue 'flowers' growing on them
2. Fractal sphere run through with non-Euclidean tubes that bend light by 90 degrees
3. Golden idol of storm god with cornetite 'clouds' spilling out from his fanged mouth

 Fossiliferous limestone:
1. Framed slice of stone artfully depicts the transition into an age of mass extinction
2. Set of spiral-shaped stone bowls intended for eating shellfish
3. Stone box designed for interring the severed head of an enemy, symbolically consigning them to extinction
 

 Malachite:
1. Slices of crystal contain delicate bands that record the songs of the vanished whales of the earth
2.  Polished sphere intended for use as a false eye
3.  Stone dagger with rippled blade

 Mesolite:
1. Spherical pom-pom bauble dangling from thin cord
2. Abrasive pad with silver handle, used for exfoliation by decadent nobles
3. Ceremonial wig attached to grimacing demonic mask
4.  Tiny diorama of snowbound valley with carved wooden figurines representing quasi-historical battle

 Meta-autunite: 
1.  Squat, primitive statuette of ancient fertility goddess
2.  Ceremonial club used for bludgeoning sacrificial victims

 Moss Agate:
1. Semi-translucent stone that lines up with landscape to reveal ley lines. Carvings on base gives clues about where to stand
2.  Polished cube containing 3D image of a floating island
3. Sword with jewel in pommel. Moss design continues along crossguard and is etched into the blade

 Pyrite:
1. Ceremonial shield. Far too heavy for practical use, but does deflect beam attacks.
2. Irrational Rubik's cube/puzzle-box that can only be solved by the insane
3. Cubic wreath, originally hung around the necks of victorious generals
4. Brutalist throne

Sewer-Guilds of the Fetid Maze

Tsutomu Nihei

Beneath the streets of the City of Shuttered Windows, there is a network of sewers called the Fetid Maze. All the detritus of the city passes through these tunnels, not only human excrement but garbage, offal, corpses and stormwater runoff. After flowing through a tangle of sluicegates and switchback tunnels, the sewers ultimately join together into the Great Sump, an enormous tube that spirals deep into the earth. The Sump is home to a series of Guilds, each a subterranean community with its own insular culture. The Sewer-Guilds have a simple treaty with the city above: anything thrown into the sewers is theirs to keep, but they are never allowed to appear above ground.

Geof Darrow

The Sewer-Guilds also have much more complex treaties among themselves. The bounty of the sewers is divided between them according to the category of waste. Stealing or tampering with something that belongs to another Guild will incite revenge-killings or even war.

First come the Gold-Pickers, who live in the tunnels of the Fetid Maze. They fish out corpses with boathooks, strip them of valuables (anything from jewelled necklaces to mouldy boots) and then return them to the flow. To help them hunt, they breed sightless moles that sense metal using magnetic organs in their foreheads. The Gold-Pickers sell their catch in the basements of disreputable alehouses.

Junji Ito

The Fat-Scrapers live on stone islands near the mouth of the Sump. They use fine mesh nets to strain grease out of the water, or occasionally luck into seizing an enormous fatberg as it comes down the pipe. They boil the fat in great tureens to remove any trace of water, and use it to make excellent tallow lamps that they sell to the other Guilds. The boiling process means their houses and clothes are always coated in a layer of congealed lard. On the upside, they are known for their delicious deep-fried cooking.

Further down the Sump are the hanging net-gardens of the Dream-Sievers. They live in narrow tunnels in the ceiling, swing about on ropes, and weave together the roots of the Night-Mandragora to catch the dreams of the city above. Dreams leave behind a physical residue, and when this psychic runoff is collected in large quantities, it can be distilled into a gaseous potion. A long stairway leads up from the home of the Dream-Sievers to the shadowy House of Vapours on the city surface. Here, oracles inhale the zeitgeist of the city to give political advice to noblemen or crime lords.

Next come the Corpse-Farmers. Often maligned as anthropophages, in reality they are vegetarians. They only collect corpses to use them as beds for the growing of strange fungi. Mushrooms grown in the bellies of horses give a rush of stamina; mushrooms grown on rat corpses are small and salty; mushrooms grown in the wounds of murdered men will bring dark dreams. The halls of the Corpse-Farmers will look like a nightmare abattoir to someone from the surface world, but in their own view they are merely making use of something that would otherwise go to waste.

Moebius

All the Sewer-Guilds worship some form of storm god, and take great pains to propitiate him. In the sewers a rain storm is both a calamity and an opportunity, bringing danger with its floodwaters but also carrying fresh bounty down the pipes. The upper Guilds at least have contacts on the surface to warn them when rain is coming. Not so for the Gong-Shepherds, who dwell deep in the Sump and have never seen the sun. They claim exclusive rights to the shit and piss of the city. They clump together massive floating islands of feces, in whose hyperrich soils they plant fields of Black Emmer wheat. When a great flood comes, the Gong-Shepherds must move their islands into sheltered coves or risk being washed away. They also know how to distil saltpetre from urine, and use it to make crude firework guns to fend off the fanged lizards of the deep.

The last Guild is the Wood-Takers. They wear wooden masks, silk robes and jewellery of strange design. They claim all the wood that floats down the sewer. If even the smallest spar is stolen, they will know about it, and they will come with silver daggers to exact their revenge: a pound of flesh for a pound of wood. They do not use the wood themselves, but carry it away into deeper tunnels. Some speculate that they sell it on the shores of an underground sea where it is fantastically valuable.