Althor's Abacus

Source
This item can be found inside the Gunship Armory after winning the Gunship Battle in the 25-man version of Icecrown Citadel.

There is also no lore about anyone named Althor within the game, however it can be inferred that at one point he was a powerful mathematician.

Effect
The proc is called Echoes of Light, and it can crit. While killing a few bosses in ICC25 normal, a resto shaman with 4T10 and 3200 spellpower unbuffed got ~65 procs from ~930 spells cast for about 2% of the total healing output.