Beljuril

Beljurils, also known as fireflashils or fireflashes, were gemstones unique to the Realms and highly prized for their unusual properties. These jewels were found in ancient rock formations, usually in blue claystone.

Description
Beljurils were a deep seawater green with a smooth surface, and all known specimens were roughly the size of a human fist approximately 3 to 5 in (8 to 13 cm) in diameter and not quite spherical. These stones were extremely hard to abrade or cut&mdash;mere metal tools wore out quickly and had to be replaced often to make any progress. Because of this, when worn for adornment, they were usually worn uncut or split into halves and mounted in claw settings for pectorals or epaulets. Other mundane uses include beljuril shards as decorative lighting, warning beacons, or nightlights for the extremely wealthy. A typical specimen had a base value of 5,000 gp.

Powers
About once every hour (rates varied from stone to stone and did not seem correlated with size or age) a beljuril absorbed an undetectable amount of energy (heat, light, and vibratory) from within a 30 ft (10 m) radius and re-emitted that energy as a flash of light without heat or sound but with a few very mild sparks of electrical discharge. The light produced was easily noticeable when the ambient light was dim (candlelight or lantern light) and in the dark it was dazzling to the eye.

Alchemists, artisans, and sages attempted to harness beljurils as a power source, but none were known to have succeeded. This stone's affinity for electrical energy made it highly desirable as a component in making wands of lightning and other items that cast electricity spells&mdash;shards of beljuril affixed to the tip increased the power of the wand or made it harder to resist, depending on the nature of the spell. Likewise, powdered beljuril was used in ink for inscribing such spells and in magical immersions to enchant items that collected or conducted electricity.

Rumors & Legends
A dwarven legend told around the southwestern region of the Vast asserted the existence of a natural cavern somewhere northwest of High Haspur whose walls, floor, and ceiling were encrusted with thousands of beljurils. The legend was unspecific about how to access the cave or what may have been guarding it, but warned that all who sought the cave vanished entirely or were found dead with a single beljuril stuffed into his or her mouth.

Notable Beljurils

 * Dyrr the Lichdrow used a beljuril for his phylactery.
 * The Wyvern Crown of Cormyr was studded with jewels, including beljurils.
 * The King's Crown of Tethyr, worn by various monarchs including Haedrak Rhindaun III, had a beljuril as the centerpiece of the diadem.
 * The Beljuriled Belt of Battle was one of three gifts given to the Coronal of Cormanthyr by the dwarves in appreciation for their new homeland.
 * Magical clothing known as Tasmia's heart was decorated with beljurils and sapphires.
 * The kiira N'Vaelahr were 24 enchanted sigils, each formed by combining a beljuril and an emerald into one magical item.
 * The Hall of Sparkling Stones in Mirabar had beljuril shards sprinkled about the walls and balconies of the multistory central chamber.
 * The Jaezred Chaulssin's House of Hidden Masters had a chamber whose ceiling was made of arches of black onyx studded with beljurils.
 * One branch of Malaeragoth the Unseen's lair under the Greypeak Mountains was illuminated by twinkling beljurils.
 * The eyes of Nearal were a matched pair of beljurils thought to be part of the hoard of the great blue wyrm Iryklathagra ("Sharpfangs").
 * The eyes of Geb were another pair of matched beljurils thought to be among the hoard of Alasklerbanbastos, a dracolich.
 * Beljurils were favored by the gods Corellon, Deep Sashelas, Flandal Steelskin, and Mystra.
 * A beljuril was one of the things the goddesses Leira and Mystra (and Mystryl before her) were occasionally known to send those they favored.
 * Half the pieces of the Magical Chessmen of Ultham-Urre were inlaid with beljuril shards, making the "green set". The "red set" was inlaid with tiny jacinths.
 * Jhauntar Olmhazan, proprietor of Olmhazan's Jewels in Waterdeep, used beljuril shards to give his displays sparkle.