Advanced Potions Textbook

This textbook details the steps, processes, and ingredients (with a list of expensive substitutes) required to create high-level potions.  Each potion has a key item that reduces the cost by 50% and/or may be required at the DM's discretion. The book details the following potions of rare quality:

• Elixer of Health - Strand of hair from a Cestial type creature.
• Oil of Etheralness - Essence of a creature that dwells on the Ethereal Plane.
• Oil of Sharpness - Adamantine shavings.
• Potion of Clairvoyance - The Eye of a sentient creature.
• Potion of Diminution - A pinch of Pixie Dust.
• Potion of Fire Giant Strength - Finger or Toenail of a Fire Giant.
• Potion of Frost Giant Strength - Finger or Toenail of a Frost Giant.
• Potion of Stone Giant Strength - Finger or Toenail of a Stone Giant.
• Potion of Gaseous Form - Air or Water Elemental Essence.
• Potion of Heroism - Four-leaf Clover.
• Potion of Invulnerability - A chunk of naturally occurring Pure Iron. 
• Potion of Mind Reading - The Brain Fluids of a sentient creature.

Crafting - 2000gp (reduced by 50% with the proper item), 4 hours, DC 17 Intelligence (Alchemist's Tools) check or lose half the material value (not the key item). The check can be made with advantage with the help of a familiar or creature proficient in Arcana, Nature, or Alchemist's Tools to assist you. Increase to DC by +2 for each additional brewing cauldron.