Skies of Glass
Spirit Silver is a very soft, silver metal that seems to weep a faint amount of gaseous light. The metal comes from Ikari most commonly and is formed from kami passing through a normal vein of silver over the course of many, many years, making it incredibly rare. Spirit Silver is highly valued by Crafters because of its almost unparalleled ability to absorb magic. The metal makes weak armor and weapons but both can be incredibly useful in different situations. Spirit Silver has 8 hit points per inch of thickness and hardness 5.
Spirit Silver weapons overcome DR/Silver and all weapons made of Spirit Silver are treated as if they have the Ghost Touch and Spell Storing enchantments. However, on a successful attack with a Spirit Silver weapon, the wielder takes a –2 penalty on the damage roll (with the usual minimum of 1 point of damage). Spirit Silver weapons cost an additional 18,000 gp and are automatically considered masterwork.
Spirit Silver armor counts as once size category less (minimum light) and has its spell failure decreased by 10%, maximum Dexterity bonus is increased by 2, and armor check penalties are lessened by 3. Spirit Silver armor is treated as if it has the Ghost Touch enchantment. Light Spirit Silver armor costs an additional 17,000 gp, Medium armor costs an additional 24,000 gp, Heavy armor costs an additional 30,000 gp, Shields cost an additional 17,000 gp.
Spirit Silver is an inherently highly magical metal, and thus Crafters attempting to transmute it require 20% of the desired value in ectoplasm or similar spiritual remains (so a Crafter attempting to turn regular iron into 10,000 gp worth of Spirit Silver would need 2,000 gp worth of ectoplasm) and the material must be exposed to a kami for the entirety of the transmutation (most often requiring the assistance of a Shaman or an intelligent kami). Only the creature components are consumed in the transmutation, the kami is unharmed.