A Spellstone is created by the warlock [Create Spellstone]spell, increasing damage done by damage over time effects by 1% and increasing spell haste by x. See Spellstones for general information.
Other Ranks
The regular Spellstone (as seen above) is created by Rank 1 of the Conjure Spellstone spell. Other ranks exist:
[Create Spellstone] spell, increasing damage done by damage over time effects by 1% and increasing spell haste by x. See Spellstones for general information.
Patch 4.0.1 (2010-10-12): Removed. 
