Find all four Master Ore pieces by searching the following locations and performing the corresponding tasks:
MASTER ORE PIECE
LOCATION/HOW TO FIND
Thieves' Hideout; After you find the Thief Girl and escort her out of the dungeon, you'll encounter a room in the Basement filled with water. At the southwest corner of this room, there are a pair of floor switches. Step on one switch and have the thief girl step on the water, making the nearby wall open. Run down the long hallway and open the treasure chest to get the Master Ore.
Skull Woods; Located in one of the last rooms of the dungeon where Link needs to get the two Eyeballs. One of the eyeballs is found on the higher ledge at the south end of the room. There is a large treasure chest just north of the eyeball. Link can merge along the wall to reach the treasure chest that holds the Master Ore.
Dark Palace; Note: Bombs are required. On the 2nd floor of the Dark Palace is a room with six windows where light shines in. Just north of this room there is a small rectangular room with a treasure chest. In order to reach this room, first be sure the platforms in the center of the room are lowered. There are two switches, and while both activate the platforms, the lower switch also causes the wall to the north to flip when it is hit. Place a bomb next to the bottom switch and quickly run northward to the platform above. Strike the nearby switch to get to the higher ledge and run to the northern wall. Once the bomb explodes and hits the southern switch, the wall will flip, causing Link to enter the small rectangular room. Open the treasure chest to get the Master Ore.
Lorule Graveyard; Note: Titan's Mitt are required. Head to the Sanctuary in Hyrule and use the crack to enter Lorule. Exit to the south and walk eastward to the graveyard. At the northeast corner of the graveyard, use the Titan's Mitt to lift the big boulder and head down the steps. Press the switch found at the west side of this cave and go through the door that opens, then make your way to the northwest part of the room and climb the steps. Walk along the path to the right until you reach a treasure chest. Merge along the wall to the east and walk on over to the small key. Use the locked on the locked door to the northwest. Take out the three red Eyegores that appear and then head up to the next room. Pull the switch on the right and then head up the staircase.Merge along the wall to the right to reach the large treasure chest and open it to get the Master Ore.