Chests

There are a total of 32 chests to be found within the mines of Mythrock that contain all manner of goodies. Of those, 13 will just be standard chests right out in the open, and 19 will be hidden chests that you can reveal by blasting them with Fire. The hidden ones can be easily found by making use of Odin Vision.

Spires of Agdor

None Entrance hall

None Winding Stairs

Type: Standard
Location: Head down the first set of stairs and walk over to the second set. With the second stairs at your back, the chest will be visible.
Contents: Gold

Type: Hidden
Location: Head down the second set of stairs and summon Odin. Use Odin Vision to spot the invisible chest near the top of the third set of stairs. Zap it with the wand to reveal it.
Contents: Large Key

Type: Standard
Location: In the room with the exit door, across from the Message Sphere.
Contents: Red Potion

The Cage

Type: Hidden
Location: Once you clear out the giant spiders and enter the cage, summon Odin and gaze through his eyes to spot a hidden chest.
Contents: Shield, Large Key

The Alcoves

Type: Standard
Location: Head forward from the entrance. The chest is in a small alcove across from the Blue Barrier.
Contents: Purple Potion

Type: Hidden
Location: This is behind the red barrier near the Large Key. You can use Odin Vision across the hall to help spot this.
Contents: Gold

Type: Hidden
Location: Once you reach the Save Point beyond the Blue Barriers, burn the tapestry across from Odin's perch and head down the hidden stairs. Head forward a bit to the stone relief with the Tablet on it. Summon your raven familiar, and Odin's vision will highlight a hidden chest on his left.
Contents: Blue Potion

Type: Hidden
Location: When crossing the bridge of spike traps, place the second Rune Tablet and then shoot the nearby hidden Chest . This can be easily spotted by using Odin Vision from the pedestal near the exit door.
Contents: Gems

Dark Halls

Type: Standard
Location: Turn left at the first intersection and head all the way to the end of the hall. Zap the fake wall, and the chest can be found just past where the wall was. Once you pass the halfway point of the hall a gate will close behind you, which makes it possible to open this later once the blue beams are blocked.
Contents: Gems

Type: Standard
Location: After the first magic missile hallway is a chasm room with a line of pillars bisecting it. Cross the pillars, then edge out onto the walkway remains on the left. Use the rope on the wall to shimmy back across the chasm. Near the other side is a chest on a ledge that you can climb down to.
Contents: Red Potion

Type: Hidden
Location: In the chasm room behind the illusory wall. Make your way across to the table to turn off the blue beams, then turn back to the entrance. There are ledges to the left and the right. Make your way to the ledge on the left and summon Odin. Use his vision to spot a nearby hidden chest.
Contents: Gold

Type: Standard
Location: In the short hall containing the exit door.
Contents: Gold

The Forge

Type: Hidden
Location: When you first enter area, use Odin Vision to spot a hidden chest to the right.
Contents: Blue Potion

Type: Hidden
Location: Use the elevator to reach the second tier and summon Odin. His Odin Vision will show a hidden chest to the left of the stairs leading to the lava pool.
Contents: Gold

Type: Standard
Location: On the second tier, use the rope to cross the lava pool. Move forward a bit and then enter the small room on the right.
Contents: Blue Potion

Mine Maze

Type: Standard
Location: Moving forward from the entrance leads you to a T-intersection. To the left is a Save Point, but to the right is a dark alcove with this chest. This is missable if you go to the Save Point first.
Contents: Gems

Type: Hidden
Location: There's a spot where you pull a lever, then turn around to destroy an illusory wall to reveal a lever surrounded by blue torches (also a large slug). You can use Odin Vision to find this chest near the lever.
Contents: Golds

Type: Hidden
Location: After disabling the Red Barrier, summon Odin and use his power of sight to find this hidden chest nearby.
Contents: Large Key

Type: Standard
Location: At the end of the mines, there's a wooden bumper at the end of some mine cart tracks. The chest is in front of the bumper.
Contents: Red Potion

Western Mine Shaft

None Blue Room

Type: Hidden
Location: After arriving at the bottom of the mine track, approach the large door and summon Odin to one of the nearby perches. Use Odin Vision to spot a chest near one of the large boulders.
Contents: Purple Potion

The Prison

Type: Hidden
Location: After finding the Ice magic and dispelling the barrier, make your way to the small island with a Save Point on it and nothing else around it. You can use Odin vision to find this.
Contents: Large Key

Eastern Mineshaft

None The Forge (Revisited)

Type: Standard
Location: After returning to the Forge via the Eastern Mineshaft, this is shortly before the destructible rubble.
Contents: Red Potion

Rising Stairs

Type: Hidden
Location: On the second landing, face the small fountain. This will be to the the right of the fountain, and can be revealed with Odin vision.
Contents: Large Key

Dungeon Cells

Type: Standard
Location: On the first floor, this is in the cell with the troll.
Contents: Red Potion

Type: Hidden
Location: On the third floor. If you get yourself in between the blue energy barriers and face the levers, this will be just past the barrier on the right. It's at the edge of the crumbled floor past where the cell door would be. Quickest way to get this is to shoot it from near the levers, then drop the barrier and run to it.
Contents: Gems

Stone Maze

Type: Hidden
Location: At the second Save Point, in front of the blue energy barrier. Use Odin Vision to see this across from his pedestal.
Contents: Large Key

Type: Hidden
Location: In the room with the pressure plate traps, summon Odin at the bottom of the stairs. Use his Odin Vision to spot this chest to his right.
Contents: Blue Potion

Type: Standard
Location: In the room with the pressure plate traps, sitting in plain view against the wall opposite the stairs. Be careful of the pressure plate directly in front of it.
Contents: Red Potion

Type: Standard
Location: Move through the open snowy cavern and dispel the red barrier, then continue moving through the halls. Dispel the illusory wall near the blue barrier and find this chest in the alcove.
Contents: Gems

Type: Hidden
Location: Freeze the underground lake and dart across to the large ventilation pipe. You can use Odin Vision from the dock to help you locate this hidden chest in the pipe.
Contents: Large Key

Type: Standard
Location: After crossing the underground lake, continue through the maze until you find the runic plate that dispels the red barrier. The chest will be in plain view near it.
Contents: Purple Potion

Dragon Cavern

Type: Standard
Location: Face the large trap rune. Turn right, and make your way past the boulders to find this tucked away near the wall. This is far enough away from the dragon to avoid his deadly fire, so you can grab this before freeing him if you wish.
Contents: Red Potion