Beljuril dragon

Beljuril dragons were a rare but powerful species of gem dragon that lived only in seismically active areas. Their namesake and favored gemstone was the beljuril, which was unique to Toril.

Description
Beljuril dragons were dark grey when they hatched, but slowly developed a lava-like coloration, with grey or black plates interspersed with red and yellow outlines. Older beljuril dragons lost this coloring, instead developing dark grey and violet scales streaked with incandescent blue and green. They ranged in size from wyrmlings to  great wyrms.

Personality
Beljuril dragons were reclusive by nature, being limited to seismically active regions as they were. However, younger beljuril dragons tended to be curious about any and all visitors. Beljuril dragons were almost never violent unless attacked, or the rare times an older one sought a new territory.

Abilities
Beljuril dragons possessed two breath weapons: the first was a silent, cold blast of energy that discharged as a bolt of green, violet, or blue light that crackled and flashed. It absorbed heat, light, and vibratory energy and released a massive electrical blast. Interestingly, it sometimes left behind a handful of beljurils; the dragons could only use it in a seismically active environment. The second breath weapon was a gout of lava. Beljuril dragons were wholly immune to any and all fire- or heat-based effects.

Like other gem dragons, beljuril dragons were naturally psionic. They typically had the psychokinetic sciences of molecular rearrangement and telekinesis, the devotions of control flames, control wind, inertial barrier, molecular agitation, and molecular manipulation, as well as the psychometabolic sciences of energy containment and metamorphosis, and the devotions of cell adjustment, chemical stimulation, lend health, and suspend animation.

Combat
Beljuril dragons rarely started combat, and their inhospitable habitat protected them from most threats.

Ecology
Beljuril dragons fed upon seismic energy, and were consequently limited in habitat to seismically (volcanically) active areas. They made their homes in the lava lakes and surrounding caves that formed at the top of volcanoes: a fearsome and wondrous environment where curtains and fountains of fire sometimes appeared, over a black crust of dried lava that tore because of movement in the liquid beneath. They rarely left their lakes, except when an eruption was imminent, when they took flight to find a new lake.

The treasure they "kept" in their lairs consisted of molten silver and copper in the lakes, sometimes with gold deposits underneath, or other rare ores drawn up from the mantle of the world. The solid rock around their lairs was always studded with beljuril crystals (they filtered seismic energy through the stones while feeding), as well as quartzes or rainbow obsidian some 60% of the time. Many beljuril mines were found over old beljuril dragon lairs.

Adult and older beljuril dragons would leave their homes to collect meteorites, which they used to aid them in spellcasting and arcane rituals. The only magical items ever found in a beljuril dragon's lair were those that could withstand the immense heat.

Beljuril dragons were natural loners. They laid and buried their eggs deep within the ground, and new dragons only hatched at the same time a new volcano formed. Interestingly, wyrmlings hatched with unusually hard scales (due to the heat and pressure of where they hatch), but lost that hardness from youth to young adulthood, when frequent growth spurts necessitated frequent shedding.

Beljuril dragons spoke their own dialect of Draconic, as well as the dialect common to the gem dragons.

On Faerûn, beljuril dragons weren't just reclusive, they were incredibly rare at only eight or nine adults. They relied on their psionics to keep dwarves and gnomes away from their homes. One of them was known to lair in a lava cavern deep beneath the easternmost Spiderhaunt Peaks (north of Semphar).

History
According to some sages, beljuril dragons were a remnant of a time when "oceans of magma lapped against the shores of young continents".