In Fletcher Manor in the Hillsbrad Foothills, Zachariah acquired a vial of strange, crystallized slivers of the void from a being of the void.
He later brought these crystals with him from the Eastern Kingdoms to Kalimdor, where he eventually laid them into part of a dark ritual in the Wailing Caverns.
This act appeared to amplify whatever ill the ritual was enacting, and later spurred forth a bizarre creature whose body was littered in dark, crystallized shards.
When he then collected these new, dark shards, the elven archdruid Naralex requested to take at least some of the shards so that he could study them.
Zachariah opted to give the archdruid all the crystals he had at hand, which Naralex would then take to Moonglade.