Made by the Formari, these lyrium-infused rings are supposed to help apprentices retain their lessons. They work rather well--too well, perhaps, as less-capable students sometimes wear three or four per finger. This ring boosts experience points by 1%.
Because the game will always round fractions down, this item provides no additional experience on gains of less than 100 points.
By the time you get to level 24 a 1% increase in XP would result in an extra 1725 XP, enough to get you 12.7% of the way to level 25 (less, actually, because this calculation doesn't account for the loss of XP to the above-mentioned rounding error), but not worth tying up one of your ring slots for the entire game.
This item was originally only available to players who pre-ordered a copy of Dragon Age: Origins from any retailer.