Diamond Dust and Diamond Berg

Diamond Dust and Diamond Berg are two of the more powerful single-target Mercury Psynergies, first appearing in Golden Sun: The Lost Age. In The Lost Age, they are exclusive to Piers when he is in his Mariner class series (only Mercury Djinn set). In Golden Sun: Dark Dawn, Amiti has access to these Psynergies when he is in the Aqua Squire class series.

Diamond Dust
An "attack with crystalline ice", Diamond Dust resembles a long group of large chunks of ice slamming into the enemy. It is learned at level 12, and is available to Piers when he is at the Commander class or lower and to Amiti if he is in the Aqua Prince class or lower. Diamond Dust costs 6 PP to cast and strikes the target with Mercury power equal to the user's own attack power with 34 damage points added to the result.

Diamond Berg
Described as "freez[ing] and crush[ing] a foe", Diamond Berg will replace Diamond Dust after Piers reaches the Captain class and Amiti reaches the Aqua Lord Class. It appears as a massive block of ice (the namesake iceberg) crashing down upon the target. Piers/Amiti then physically strikes the frozen foe repeatedly, chipping off more ice with each blow. The animation changes slightly if Amiti is using a Bow; he will shoot arrows in a rapid-fire fashion rather than physically strike the opponent.

Diamond Berg is often regarded as Piers's "ultimate" attack by players, in spite of the fact that its high cost puts a strain on his low Psynergy supply (compare to Odyssey). Diamond Berg costs 17 PP to use and strikes the target with Mercury power equal to the user's own attack power with 92 damage points added to the result.