From the Blight Lord Lair (Quest) introduced in Seeds of Corruption.

Aerlinthe Gatestone
Aerlinthe Gatestone
Value: ???
Unknown Burden


Notes

You do not have enough Blighted Mana Shards to pass through to the Blight Lord's lair.

You allow Halaetan Gatestone to examine your Blighted Mana Crystal.
You hold the Blighted Mana Shard against the gatestone to no effect. You get the sensation that simply trying to use the gatestone with at least 20 Blighted Mana Shards in your pack will activate its powers.