Difference Between Emerald, Ruby & Diamond Light in FFIX

Carbuncle

• As with all other skills and spells in "Final Fantasy IX," Carbuncle is learned by acquiring ability points (AP) while a specific item is equipped. Most, although not all, summons for both Garnet and Eiko are learned through gemstones and minerals, such as pumice, opal and amethyst. The Carbuncle summon is learned for Eiko by equipping the item Ruby. Once the spell is learned, Eiko can change the effect of summoning Carbuncle by equipping a different item. Unlike other eidolons, Carbuncle only casts beneficial spells and never attacks enemies.

Ruby Light

• Carbuncle's default effect is "Ruby Light." Once the summon is completed a short animation of Carbuncle is shown leading to the "Reflect" status placed upon the entire party. Reflect, also called Wall in previous FF games, causes most spells cast directly onto the party member to reflect back to the caster. These include healing spells that allies cast. The spell has no effect on character's with the "Auto Reflect" skill equipped.

Diamond Light

• Equipping Eiko with the Diamond item changes Carbuncle's effect to "Diamond Light." This spell leaves the entire party with the "Vanish" status. Vanish, also known as "Invis" and "Invisible" in other FF games, causes the affected party member to disappear, which greatly reduces the chance of an enemy to land any physical attacks.

Emerald Light

• With the Emerald item equipped, Carbuncle's attack changes to "Emerald Light," which gives the party the "Haste" status effect. Haste, also referred to as "Fast" in FF Games, greatly increases the speed of affected party members. The spell does nothing to characters with the "Auto Haste" skill equipped.

Pearl Light

• Giving Eiko the Moonstone item changes Carbuncle's effect to "Pearl Light." The spell casts "Shell" on the entire party. Shell is a white magic spell common to "Final Fantasy" games, at times called "MBarrier." Shell halves the impact of all magic spells cast on the character, including both damaging and curative spells. Similar to other Carbuncle spells, Pearl Light has no effect on characters with "Auto Shell" equipped.