Obsidian Shard

s are objects that fell from the sky...

… made of volcanic glass ... which fell from the shattered moon …

... imbued with magic ...

''“I told you, Aren, everything has its opposite. As I represent the ancient Virtues, the magic of the shard represents dominion. You must destroy it or the Virtues will have no space to take hold, no room to grow.”'' ''“All right,” Aren said with a sigh. “How do I destroy magic purpose?”'' ''“By destroying the great shards,” she said. “There are two: one in the place where the rivers cross, and the other in the seat of Obsidian power.”''

… that was tapped by the young sorcerer …

''It was the book that had led him to cross the Vaughban Mountains and into the Grunvald plain. It brought him to the first of the Shard Falls. The shining crystalline stone, black and enormous, stood plunged like a dagger into the vast flatness around it …'' … It was the heart of a magic the like of which the young man had never before experienced, and he was drawn to it without ever once questioning the wisdom in doing so.

… who was destined to become the Obsidian Eye.

Locations
There are four primary locations where concentrations of this meteoric substance have been discovered:
 * 1) Grunvald Shardfall
 * 2) *The Epitaph (the seat of Obsidian power)
 * 3) Paladis Shardfall
 * 4) *The Confluence Chamber (the place where the rivers cross)
 * 5) Quel Shardfall (the result of a relatively recent month-long meteor shower )
 * 6) Verdantis Shardfall

although Obsidian Chips, frequently a required reagent in casting Chaos Magic spells or crafting artifacts, can be found scattered throughout New Britannia.

Properties

 * Repository and emitter of Chaos Magic

"The truth was that Obsidian magic, despite its roots in the ancient Fall and generations of study, remained an imprecise and largely unpredictable craft. Its power unquestionably emanated from the shards that plunged violently from the sky at the time of the Fall, rending the Earth and transforming its features. Yet despite the presence of this power in the world for centuries, and the many decades in which the Obsidians had been studying and practicing to understand and harness its seemingly limitless capabilities, the power itself remained a mystery and its effects volatile and mercurial."

"Everywhere else into the distance the grass was brown in the cold winter air, but around the Fall were a variety of plants and animals and even what the young man had thought were both plants and animals weaving and reweaving themselves into strange and wondrous forms, only to shift again into new shapes, both chaotic and ordered at once."
 * Emanations from larger Obsidian Shards can negate the Blessing of the Oracle.
 * Distortion of flora and fauna in the immediate vicinity.

Trivia

 * The Epitaph is not located underneath the Grunvald Shardfall, but is referenced as stating that the area derives its power by from the Grunvald Shardfall:
 * He knew the place well, for it was his own chamber deep beneath the fortress of Desolis - a ruin from before the Fall that his young order of sorcerers had claimed for their own. It was near enough to the Shard Fall  that magic could be wrought here and far from the prying eyes of the petty warlords who were constantly battling one another in the wake of the world's collapse.
 * ... inhabitants of the region had called Epitaph. It was a mountain plateau of stone that had been thrust up from the ground at the time of the ancient Shard Fall and had carried a great deal of the surface skyward in the process.  It was largely comprised of sandstone infused with the ruins filled with ash and marbled with cold volcanic flow.  It was the latter, however, that gave the site special significance to the Obsidians, for the lava tubes that had formed carried the power of the Shard Fall directly into the caverns beneath Epitaph...