Black sapphire

Black sapphire was a rare variety of sapphire found mainly in south Faerûn, particularly around the Great Rift where the dwarves of the Deep Realm prized them greatly.

Description
These stones were an inky, lustrous black that reflected white or yellow highlights and were facet-cut in the same way as their blue cousins.

Powers
When cut and polished, a jewel-quality black sapphire prevented time-related spells from operating within a range of. Spells such as temporal stasis, time stop, and spells from the arcane chronomancy school or divine time sphere all ceased functioning, either temporarily or permanently, depending on the nature of the spell. These gems could also be used in the creation of exceptionally powerful wands that stored spells like darkness and related magics. The darkness effects produced were either more difficult for the target to resist or the strength of the spell increased, again, depending on the nature of the spell.

The shadow magic item helm of darkness used a large black sapphire and thirty-six black opals in its construction.

Price
A typical specimen had a base market value of 5,000 gold pieces.

Notable Black Sapphires

 * The Wyvern Crown of Cormyr was studded with jewels, including black sapphires.

Notable Users

 * Black sapphires were considered prized gems among the drow, being one of their favorites.
 * The drow deity Vhaeraun sometimes showed his favor or disfavor with black sapphires.
 * The drow deity Lolth sometimes showed her favor to followers by having them discover black sapphires that had spiders encased in them.
 * Black sapphires were sacred to the Chultan demigod Eshowdow, who also valued unholy items made of the material.