Things You'll Need
Instructions
Play the game up to the point where the party finds the Great Whale, travels to the moon and destroys the Giant of Bab-il. You will also need to have already completed the optional quest to take the "Adamantine Ore" to the smith in the underworld, and to have received the "Excalibur Sword' in exchange.
Fly back to the moon and make your way through the caves, toward the area where the evil Lunarian Zemus resides.
Keep trekking through the lunar caves until you find one marked "Lunar Subterrane B5." Explore the various rooms in this area until you find a small room with a treasure chest. Depending on the version of the game you are playing (SNES, PS1, Game Boy Advance, ROM, etc.) there may either be a "Cabin" or an "Inferno" item in the treasure chest.
Battle random monsters in this room until you are attacked by a creature called either a "Pink Puff" or "Princess Flan," depending on the version of the game you have. The creature will look a lot like the "Flan" monsters your party has battled in earlier areas of the game.
Keep fighting monsters in this room until the Pink Puff drops a "Pink Tail" item after the battle.
Leave the lunar tunnels and take the Great Whale back to Earth. Once there, locate the airship that is outfitted with a grappling hook and board it. Use the hook to pick up the hovercraft from wherever you last left it.
Drop the hovercraft down near the town called Silvera. Exit the airship, board the hovercraft and fly over the shallow areas of the sea to the nearby cave. Enter the cave and speak with the man inside, who will give you another "Adamintine Ore" item in exchange for the "Pink Tail" you got from the monster on the moon.
Go to the underworld and find the dwarf blacksmith who lives in the small house at the southern end of the map. Speak with the blacksmith, and he will forge the "Adamant Armor" for you if you give him the Adamantine Ore.