Adamantine: grants damage reduction based on armor category. DMG
Arandur: grants sonic resistance. MoF
Astral Driftmetal: effective against incorporeal attacks as if made of force, only a breastplate, shield, or heavy armor can be made from this material. PH
Aurorum: restores itself if sundered. BoED
Blended Quartz: reduces ASF. A&EG
Blueice: reduces armor category, ACP, and ASF (for cold spells) and increases MDB. FB
Bronzewood reduces weight, doesn't affect hide in woodlands. A&EG
Camoflauge Dye: grants a hide bonus (only with specific light armors). RoF
Chitin: replaces metal, increases MDB. RotD
Copper, Alchemical: grants cold resistance. MoF
Darkleaf, Elven: reduces ASF, ACP, armor category and increases MDB. A&EG
Darksteel: grants acid resistance. MoF
Darkwood (Zalantar): reduces weight and ACP (shields only). DMG
Dlarun: grants fire resistance. MoF
Dragoncraft Armor/Shield: grants energy resistance 5 against the respective dragon as an extraordinary ability. Reduces armor category and ACP, only available for certain armor types. Draco
Dragonhide: replaces metal to craft most armors. Immune to the breath weapon of the respective dragon species (armor only). DMG/Draco
Dragonhide Mantle: grants energy resistance as dragoncraft armor, but uses the shoulder body slot. Draco
Duskwood: breastplate only; reduces armor category, ASF and ACP, increases MDB. MoF
Elukian Clay: increases ACP, does not apply ACP to swim. A&EG
Entropium: increases armor category and Str ACP, reduces Dex ACP, ASF and increase MDB. A&EG
Fever Iron: grants fire resistance. MoF
Flametouched Iron: grants a saving throw bonus vs. evil outsider spells, SL and supernatural abilities. ECS
Glassteel: reduces armor category, ACP and ASF, increases MDB. RoF
Gold, Alchemical: grants fire and acid resistance, increases armor category, ACP and ASF, decreases MDB. MoF
Leafweave, Elven: reduces ASF and ACP, increases MDB, cannot replace metal armors. A&EG
Living Metal: reduces ACP and ASF, increases MDB. MoF
Mithral: reduces armor category, ACP and ASF, raises MDB. DMG
Mournlode, Purple: resistance bonus vs. the spells, SL and supernatural abilities of undead. MoE
Platinum, Alchemical: grants cold and sonic resistance, increases armor category, ACP and ASF, decreases MDB. MoF
Riverine: half the armor bonus becomes deflection (see misc. for more properties). SW
Sentira: replicates mithral, required to craft emotional armor (emotional armor has some pretty decent bonuses. All three are published in the same book: Calming, Dreadful, and Vengeful). SoS
Shadowsilk: can only be used to make certain light armors, grants a bonus to hide/move silently, increases MDB, reduces ACP and ASF (in shadows/darkness). ToM
Starmetal: replicates adamantine. CAr
Susalian Chainweave: grants damage reduction /piercing. CM
Thistledown: used for padded armor, provides a bonus to hide checks in shadowy/dark areas. RotW
Urdrukar(mindsteel): increases the DC vs. scrying on the wearer, doubles ASF. A&EG
Wildwood: reduces the AC bonus, ACP and ASF, increases MDB and has no ACP when used to hide in undergrowth. Wildwood heals itself if soaked in water or while in sunlight. RotW
Ysgardian Heartwire: increases AC vs. crit comfirms. A&EG