Crystals

Crystals (結晶) in Sword Art Online are considered to be one of the most convenient types of items and the closest thing to magic in the world. They have different uses, namely having immediate effect for recovery unlike potions and perform a variety of function outside of healing, extending to teleportation, corridors to locations, and displaying images or replaying voice messages.

Though extremely useful, they are expensive hence making people hesitant to use them, unless they are in very special (dangerous) situation. Most of crystals can be found through some NPC shops, except for the Corridor Crystal. Corridor crystals are the rarest of all crystals, and are only obtainable by trading with other players, or from killing monsters or obtaining them from a treasure chest.

Their usage can also be prevented by a trap called an anti-crystal field, which became normal for boss fights on the 74th Floor and above.

Known Kinds

 * Antidote Crystal (解毒結晶) (Green) - cure any status effects.
 * Healing Crystal (回復結晶) (Red) - completely heals the target.
 * Teleport Crystal (転移結晶) (Blue) - transport the user to a chosen city's Teleport Gate plaza.
 * Corridor Crystal (回廊結晶) (Indigo) - a larger form of teleport crystal that opens a teleport gate to any location that the player has marked. Corridor crystals have a darker shade of blue then the teleport crystal.
 * Message Record Crystal (メッセージ録音クリスタル) - record what someone has said.
 * Record Crystal (記録結晶) - take in-game screenshots.
 * Screen-Shot Camera Crystal (スクリーンショット撮影クリスタル) - take in-game screenshots.

Colors

 * Amaranth/Red - Full Health Recovery
 * Blue - Teleportation
 * Navy Blue with Red Dots - Corridor
 * Green - Status Recovery
 * Light Sea Green - Message Record Crystal (when recording or playback)
 * Teal - Message Record Crystal (when inactive)

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