Bonding Runestone

Bonding Runestones are a type of augments for Companions, which provide an equip power as well as offense or defense bonusses depending on the type of slot of the companion it is placed in.

Stats and equip power
The equip power Bonding Runestone provide is:"When your Companion activates a power, it will grant you Companion's Gift.""Companion's Gift grants you ..% of your Companion's stats for 30 seconds."The percentage of stats granted scales withe the rank of the Bonding Runestone, and varies from 30% at Rank 7, to 65% at Rank 14.

Refinement
For the refinement and regeants required to upgrade (Bonding) Runestones see: Enchanting