Special Crafting Materials

Also see, Weapons Refurbished and Armor as Damage Reduction.  

Metals

Silver

Cost Increase: 2 Suns per pound of the item being made or +1 Tier.
Crafting DC Increase: +2.
Soft Metal: silver items take maximized damage from materials as hard as Bronze or harder, and break on a natural 1.
Metal of Purity: particularly impure creatures often have a weakness to the pure nature Silver.  

Cold-Forged Iron

Cost Increase: 10 Suns or +1 Tier.
Crafting DC Increase: +4
Cold Forged: non-bludgeoning weapons made from Cold-Forged Iron reduce their damage dice by 1 step.
Uncorrupted Metal: particularly natural or chaotic creatures often have a weakness to the orderly nature of Cold-Forged Iron.  

Moonsilver (Mithril)

Cost Increase: 80 Suns per pound of the item being made or +3 Tiers.
Crafting DC Increase: +3.
Metal of the Maker: Mithril is considered a holy metal of Tiln, and is incredibly durable for its weight.
Highly Ductile: Mithril can be drawn into long and threads, allowing it to be woven like cloth.
Metal of Purity: like silver, many particularly impure creatures are weak to the inherent purity of Mithril. This weakness is usually more pronounced for Mithril than it is for silver.  

Stonesteel (Adamantine)

Cost Increase: 100 Suns per pound to make it from adamantine directly or +3 Tiers.
Crafting DC Increase: +5.
Metal of the Judges: Adamantine is considered a holy metal of Brumil and Makil and is incredibly hard and durable.
The Hardest Metal: Adamantine is known to cut through even the toughest hide, bypassing most non-magical forms of damage resistance or immunity and resisting damage from other materials.  

Solarium

Cost Increase: 50 Suns per pound of the item being made or +2 Tiers.
Crafting DC Increase: +2.
Metal of the Sun: Solarium is considered a holy metal of Cir and has an aesthetic and toughness similar to that of gold.
Holy Light: Solarium emits a soft, warm light that is known to be anathema to undead creatures.
Soft Metal: Solarium items take maximized damage from materials as hard as Bronze or harder, and break on a natural 1.  

Delirium

Cost Increase: 200 Suns per pound of the item being made or +3 Tiers.
Crafting DC Increase: +7.
Metal of the Changer: Delirium is considered a holy metal of Gwynn-Morro and is heavier and harder than steel. It is known to have strange effects on nearby living creatures, from mutations to sicknesses to hallucinations, etc..
Super Dense: items made from Delirium are always Heavy, and never have Finesse.
Too Heavy: Delirium items have trouble supporting their own weight and break on a natural 1.  

Blackiron (Noqual)

A holy metal of Denol. Always cold to the touch. Nearly impossible to see with non-standard forms of vision. Highly effective at cold-forging.  

Woods

Brazewillow

Cost Increase: 120 Suns per pound of the item being made or +2 Tiers.
Crafting DC Increase: +3.
Wood of the Beast: Brazewillow is considered a sacred material of Bolgarung and can only be found growing within the White Forest. 
Holy Flames: when burned, Brazewillow's flames have special properties that depend on which species of the wood is burned.  

Briarburn Brazewillow

This species of Brazewillow burns with peaceful, green flames that only catch on underbrush. Commonly used by druids and rangers for controlled burns within a forest, its green flames are still hot, but not dangerously so.  

Weeping Brazewillow

This species of Brazewillow burns with flames of a deep blue. These blue flames are unaffected by water, allowing the creation of underwater torches. They still otherwise spread and create heat just like a normal fire, so must be handled with utmost care.  

Blazing Brazewillow

This species of Brazewillow burns with flames of a deep, dark red. These red flames act as normal flames except that they burn far larger and hotter than would be expected. They catch extremely easily and tend to burn fuel at nearly twice the rate of regular flames  

Dousing Brazewillow

This species of Brazewillow burns with bright, silver flames. These silver flames shed no heat and only catch on other flames. This species is used by druids and rangers to combat forest fires.  

Magebane Brazewillow

This species of Brazewillow burns with flames of a bright yellow. These yellow flames easily catch on arcane magical auras, making them popular among mage hunters. In all other ways the flames spread and create heat like a normal fire.  

Mindflame Brazewillow

This species of Brazewillow burns with flames of shimmering purple. These purple flames spread through sight and burn the mind of that which sees them. It feeds and grows on the thoughts of its host, spreading to other sentient creatures who see it.   Mindflame Brazewillow is thought by some scholars to be a sub-species of Blackfire Brazewillow.  

Blackfire Brazewillow

This extremely rare species of Brazewillow burns with flames of darkness that hurt the eye with their brightness. These black flames burn the very essence of that on which they catch, erasing it from existence. Extremely difficult to put out, the flames are nearly unstoppable once they catch.  

Cloths

Etherium

Cost Increase: 150 Suns per pound of the item being made or +4 Tiers.
Crafting DC Increase: +3.
Fabric of the Scholar: Etherium is considered a holy material of Anglea that is made from a mixture of phase spider silk, moonlight, and a variety of other materials.
Extraplanar Fabric: Etherium exists partially within one of the Reflection Planes. Which plane it exists within depends on how it was made (usually the Etherial Plane). It can touch creatures that exist within that plane (like ghosts), but cannot travel to a plane non-adjacent to the plane it is linked to.  

Etherium Compounds

Though Etherium is usually linked to the Aether Plane, it can be mixed with other substances during formation to connect to other Reflection Planes instead.  
Umbarium
By replacing Moonlight with shadows cast by an undead creature beneath the moon you can link it to the Shadow Plane, creating Umbarium.  
Specurium
By replacing direct Moonlight with several reflected moonbeams concentrated on a single point you can link it to the Mirror Plane, creating Specurium.   
Feroxium
By replacing Moonlight with the line between darkness and light you can link it to the Wyld Plane, creating Feroxium.    

Seersilk

Cost Increase: 150 Suns per pound of the item being made or +4 Tiers.
Crafting DC Increase: +3.
Fabric of the Seer: Seersilk is considered a holy material of Ilgradnis and can only be made from the silk left over by certain worms that make their homes atop the graves or monuments of great heroes.
Silk of Prophecy: Seersilk has a variety of divinatory uses, including veils that allow sight into other planes and cloaks that obscure attempts to divine information about the wearer.      

Powders and Liquids

Explodium

Cost Increase: 150 Suns per pound of the item being made or +2 Tiers.
Crafting DC Increase: +5.
Powder of the Renegade: Explodium is considered a holy material of Mekshtiss, usually in the form of a highly explosive powder or liquid.
 

Blood Resin

Cost Increase: 80 Suns per pound of the item being made or +2 Tiers.
Crafting DC Increase: +3.
Blood of the Challenger: Blood Resin is considered a holy material of Octag and is made from a mixture of ink and blood from certain deep sea creatures.
Icy Blood: this resin moves of its own accord toward nearby living creatures. If internalized, it causes strange but powerful mutations within the host, slowly replacing their blood with itself. It is frigid to the touch.