|Use Effect||Restore all PP to one ally|
|When Usable||Battle or field|
A Psy Crystal (エナジ－クリスタル Energy Crystal) is a consumable item in the Golden Sun series. Like most consumable items, each party member can hold up to 30 Psy crystal in a single inventory slot. When used, a Psy crystal completely restores a single party member's Psynergy Points. Psy crystals can be bought for 1500 coins and sold for 1125 coins. Also, Psy crystals are considered Artifacts, meaning they can be re-purchased if sold or dropped.
 Golden Sun Psy Crystals
Psy crystals are dropped by Manticore Kings and several bosses: Saturos, when fought atop Mercury Lighthouse; the Manticore of Lamakan Desert; Toadonpa, Dodonpa's pet monster; the Storm Lizard of Suhalla Desert. Also, several of the scripted battles at Crossbone Isle reward players with psy crystals: Floor 3 is guarded by a Lich and two Fiendish Ghouls; Floor 5 features a Lizard King, two Stone Soldiers, and a Harridan; Floor 9 is overseen by a pair of Cerebi.
 The Lost Age Psy Crystals
Psy crystals are dropped by Wise Gryphons, Puppet Warriors, Grave Wights, Liches, and the Mimic of Jupiter Lighthouse. A couple of bosses also drop psy crystals: Poseidon, guardian of the Sea of Time, and the two Flame Dragons in Mars Lighthouse.
 Dark Dawn Psy Crystals
Psy crystals can also be found in the following locations:
- A treasure chest in the entrance to the Konpa Ruins contains a Psy crystal. However, it can't be reached from the ground. Players must scale the ruins from the inside, then, after acquiring Grip, climb down from the summit.
Aside from Psynergy Stones or spending a night at an inn, neither of which can be used during battle, Psy crystals are the most effective way to recover lots of Psynergy Points at once. Granted, there are plenty of other ways to restore PP: Djinn like Ether can be used indefinitely, while some armor, such as the Mythril Circlet or Mysterious Robe, gradually restore PP during battle. Also worth noting is that Adepts automatically recover PP as they walk through dungeons or across the world map. However, none of these methods work nearly as quickly as Psy crystals.
Unlike Hit Points, the consequences for running out of Psynergy Points are fairly mild. A character without any PP can still perform physical attacks, use items, unleash Djinn, and pretty much any other battle command except casting Psynergy. Also, PP can be restored through normal means even if a character has zero Psynergy Points remaining. These lax punishments, coupled with the rarity of Psy crystals, should compel players to conserve Psy crystals for situations where a character is almost out of PP. Also, if a player has very few Psy crystals available, they should be saved for when that character has a Psynergy spell that would provide a strategic advantage.
Psy crystals are perhaps best reserved for boss battles. The most obvious reason is that boss battles take longer than normal battles, putting a larger strain on a party's PP reserves. Another, less-obvious reason is that single-target Attack-based Psynergies like Odyssey and Liquifier are a simple and common strategy for defeating bosses faster. Unfortunately, such Psynergies are usually learned by classes with low PP totals, putting an even greater strain on those characters' PP pools. Should these characters run out of PP while a boss is still standing, a single Psy crystal may provide just the boost needed to win.
Prior to Golden Sun: Dark Dawn, Psy crystals were the only consumable item able to restore PP, making them vital items in late-game inventories for both Golden Sun and Golden Sun: The Lost Age. However, Dark Dawn introduces two new items (Khiren water and ginseng), both of which are considered "common items," meaning players can purchase a limitless supply of them. Also, the removal of certain minigames have made Psy crystals harder to come by. Although ginseng is easier to stockpile and may, as a result, see much more use, there is no denying that Psy crystals are the fastest way to replenish PP while outside city limits, especially during battles.
- Before Golden Sun: Dark Dawn, Psy crystals were the only consumable item that restored Psynergy Points. Even with the new PP-restoring items introduced in Dark Dawn, Psy crystals are the only ones considered Artifacts.
|Hearts||Nut • Vial • Potion|
|Stars||Elixir • Psy Crystal • Water of Life|
|Boots||Fur Boots • Hyper Boots • Quick Boots|
|Shirts||Mythril Shirt • Running Shirt • Silk Shirt|
|Rings||Adept Ring • Sleep Ring • War Ring|
|See also||Game Tickets • Tolbi • Contigo|
|Tolbi (Golden Sun)||Lemuria (The Lost Age)|
|Weapons||Assassin Blade • Burning Axe • Grievous Mace||Fireman's Pole • Hestia Blade • Mighty Axe|
|Body Armor||Cocktail Dress • Kimono • Spirit Armor||Erebus Armor • Floral Dress • Wild Coat|
|Hand Armor||Battle Gloves • Earth Shield • Guardian Armlet||Aegis Shield • Crafted Gloves • Leda's Bracelet|
|Head Armor||Adept's Helm • Glittering Tiara • Ninja Hood||Brilliant Circlet • Crown of Glory • Minerva Helm|
|Consumable Items||Potion • Psy Crystal • Water of Life|
|See also||Lucky Medals • Coins|
|HP-restoring||Herb • Rice Ration • Corn • Kaocho Dumpling • Plump Dumpling • Nut • Vial • Potion • Mist Potion|
|PP-restoring||Khiren Water • Ginseng • Psy Crystal|
|Status-restoring||Antidote • Dried Lizard • Elixir • Water of Life|
|Offensive||Bramble Seed • Crystal Powder • Gunpowder Bomb • Illusion Perfume • Oil Drop • Psy Grenade • Sleep Bomb • Smoke Bomb • Spark Shuriken • Weasel's Claw|
|Stat-boosting||Apple • Cookie • Hard Nut • Lucky Pepper • Mint • Power Bread|
|Forgeable||Dark Matter • Dragon Skin • Golem Core • Mythril Silver • Orihalcon • Quality Zol • Salamander Tail • Star Dust • Sylph Feather • Tear Stone|
|Misc.||Dream Leaf • Game Ticket • Lucky Medal • Sacred Feather|