Vial is an item mostly used by the Alchemy profession for making elixirs, oils, and potions.

Most other vials are Quest items.

Alchemy

•  [Crystal Vial]
•  [Pyrium-Laced Crystalline Vial]

In Cataclysm

Before this expansion, 5 different levels of vials were used depending on the skill level of the recipe. After Cataclysm, the  [Crystal Vial] replaced all the different levels.

The most previously trade skill oriented vials were removed from the game and converted to poor items:

•  [Empty Vial] →  [Crystal Vial]
•  [Leaded Vial] →  [Cracked Vial]
•  [Crystal Vial] →  [Tainted Vial]
•  [Imbued Vial] →  [Melted Vial]
•  [Enchanted Vial] →  [Shattered Vial]

Quest items

•  [Antidote Vial] for  [83] Venomblood Antidote in Uldum
•  [Blessed Vial] for  [64] Restoring the Light in Shattrath City
•  [Bundle of Vials] for  [2] Urgent Delivery! on Azuremyst Isle
•  [Empty Moonwell Vial] for  [48] Nature and Nurture in Felwood
  • Becomes Whisperwind Moonwell Water
•  [Rejek's Vial] for  [80] The Heartblood's Strength in Sholazar Basin
•  [Sealed Vial of Poison] for  [80] Sealed Vial of Poison
•  [Vial of Gorat's Blood] for  [21] Final Report and  [21] To Dinah, at Once! in Ashenvale
•  [Vial of Preserved Dragonsblood] for  [85] Victory in the Depths

No longer quest items with Cataclysm

• [Coated Cerulean Vial]
  • [Filled Cerulean Vial]
• [Empty Water Vial]
  • [Vial of Dire Water]
• [Empty Vial Labeled #1]
  • [Filled Vial Labeled #1]
• [Empty Vial Labeled #2]
  • [Filled Vial Labeled #2]
• [Empty Vial Labeled #3]
  • [Filled Vial Labeled #3]
• [Empty Vial Labeled #4]
  • [Filled Vial Labeled #4]
• [Eridan's Vial]
• [Nagmara's Vial]
  • [Nagmara's Filled Vial]
• [Unused Scraping Vial]
• [Vial of Black Dragonsblood]
• [Vial of Blessed Water]
• [Vial of Corrosive Spit]
• [Vial of Hatefury Blood]
• [Vial of Innocent Blood]
• [Vial of Phlogiston]
• [Vial of Primal Reagents]
• [Vial of Purest Water]
• [Vial of Sedative Serum]
• [Vial of Spider Venom]

References