Hematite

Hematite was an ornamental stone that was favored by fighters, as well as a common ore of iron.

Description
Typical raw hematite appeared as a hard gray-black crystalline mineral, or as a red stone. Gem-quality hematite had a very fine grain of crystals, and could be polished to a smooth, shiny dark gray or black stone similar in appearance to steel. It was often tumbled to make beads or cut in a baguette fashion (rectangular with beveled sides). When crushed, hematite became a blood-red powder.

Properties
Hematite weighed about to  per. In bulk, it was commonly used as iron ore.

Tiny amounts of hematite could be trapped inside sunstones, giving the translucent gem an amber or reddish hue. A similar effect could occur in iol stones, giving them a secondary golden color.

Powers
Hematite was not magical itself, but it was responsive to enchantments related to blood and life force and was used in necromancy and the healing arts. Specifically, it was used to create magical periapts for healing and foul rotting. It was said to absorb negative energy. A typical stone had a base value of 10 gp.

Only a handful of people (mostly powerful mages that kept the secret to themselves) knew that this common stone was one of the "nine secrets"—minerals that could be enchanted to become ioun stones.

Usages

 * Polished Hematite stones were a relatively cheap and common feature of jewelry.
 * Hematite was a common stone among the drow, and was worn by drow of average station. They also often used it on enchanted items.
 * The lesser deity Iyachtu Xvim was known to occasionally send hematite gems to show favor or inspire his followers.
 * The lesser deity Vhaeraun was known to occasionally send hematite gems to show his favour or disfavour to his followers.
 * Noble dao lined the interior of their structures with reflective stones and crystals such as hematite. They used these surfaces to flash light-based messages and alarms throughout their holdings.