Here's and easy match 'em up table that will make determining what gems and armor you need for which ever Velious Quest Armor you are going for.

THE GEMS

Gems can be found in Velks or Cobalt Scar

Melee
Rogue Warrior Monk Shadow Knight Paladin Ranger Bard Beastlord		 Priest
Cleric Shaman Druid		 Caster
Mage Wizard Enchanter Necromancer
Head-Crushed Coral Head-Crushed Onyx Sapphire Head-Crushed Flame Opal
Arms-Flawed Emerald Arms-Jaundice Gem Arms-Flawed Topaz
Wrist-Crushed Flame Emerald Wrist-Crushed Opal Wrist-Crushed Onyx Sapphire
Hands-Crushed Topaz Hands-Crushed Lava Ruby Hands-Crushed Topaz
Chest-Flawless Diamond Chest-Black Marble Chest-Pristine Emerald
Legs-Flawed Sea Sapphire Legs-Chipped Onyx Sapphire Legs-Nephrite
Feet-Crushed Black Marble Feet-Crushed Flame Emerald Feet-Crushed Jaundice Gem

 

THE ARMOR
Skyshrine-drops in ToV Kael-Drops in ToV Thurgadin-Drops in Kael
Unadorned Plate Unadorned Chain Unadorned Leather Tattered
Silk
Cleric Shaman Druid Mage
Warrior Rogue Monk Chanter
Bard Ranger Beastlord Necro
ShadowKnight     Wizard
Paladin      
Ancient Tarnished 
Plate		 Ancient Tarnished 
Chain		 Ancient 
Leather		 Ancient
Silk
Cleric Shaman Druid Mage
Warrior Rogue Monk Chanter
Bard Ranger Beastlord Necro
ShadowKnight     Wizard
Paladin      
Corroded Plate Corroded Chain Eroded Leather Torn Enchanted Silk
Cleric Shaman Druid Mage
Warrior Rogue Monk Chanter
Bard Ranger Beastlord Necro
ShadowKnight     Wizard
Paladin