After chasing Gongoron around Goron Island, you can enter the Goron Temple to look for the pure metal.
Goron Temple 1F
Go east and try not to let the Beamos statues look at you. You can shoot their eyes with arrows to temporarily stun them.
Pull the statue onto the switch to lower the spikes. Up ahead, there is an Armos statue that comes to life when you get close. Use a bomb on it to stop it, then drag it onto the switch up above.
Go through the path where the gate opened, then use a bomb to stop the Armos statue. Push it onto the switch. Then throw a bomb onto the crystal switch in the sand below the bridge that appeared, and quickly open the chest before it disappears. It contains a treasure map.
Then cross the bridge, fall down from the ledge, and use a bomb to stop the two Armos statues. Go south through the path that opened.
Go east and shoot an arrow at the eye switch on the wall to the east, then open the chest that appeared. It contains a red rupee.
Step on the switch below to lower the spikes, creating a shortcut to the exit.
Then go west. You will see a cracked wall. If you bomb it and go through, you can't go farther, but you can see that there is a secret door between the columns on the right. Go back to where the cracked wall was, and put a bomb between the two rightmost columns. Then go through the door that opens. In the next room, go north and down the stairs.
Goron Temple B1
Go south into the room, and you will have to kill two Bubbles. Use the boomerang to get rid of their flames, then kill them with the sword. After that, go southwest, past where the spikes were. Follow the path, and soon you will find Gongoron, but you will also be trapped with a Hinox. If you get too close to the Hinox, it will knock you down. Shoot the Hinox with an arrow to stun it, then hit it with your sword, but run away after hitting it a few times. Repeat the process until the Hinox dies.
After that, you can tap the icon at the top of the screen to switch between Link and Gongoron. Switch to Gongoron. You can tap monsters on the screen to make Gongoron jump and crash into them. If you drag the stylus far away from Gongoron, he will roll around.
As Gongoron, find all of the Chuchus hiding in the boulders, and tap each one to kill it. After all of the Chuchus are dead, the spikes will lower. Switch back to Link and have him go south. Kill the Like Like to lower the spikes on Gongoron's side.
Switch to Gongoron and have him roll across the gap at high speed. If he is moving quickly enough, he will jump over the gap.
Have Gongoron stand on the switch on his side, then switch to Link and have him stand on the switch on his side. Have Link go north to open the chest that appeared. It contains the Bombchu Bag. Bombchus are remote bombs that you can draw a path for on your map when you use them. Bombchus can go through small holes.
Have Gongoron go south. Tap each of the Eye Slugs to kill them. Gongoron can't go over quicksand. After you have killed all of the Eye Slugs, a gate to the west will open.
Have Link jump down the left side of the ledge from where he got the Bombchu Bag. Go west and then go south past the gate that opened. Kill all of the Eye Slugs to make a chest appear.
Then use a Bombchu to go through the hole in the wall to the right. Draw the path to make the Bombchu hit the crystal switch on the right. The spikes will lower, so you can go west.
Go upstairs and send a Bombchu through the hole to hit the crystal switch. This creates a bridge that gives you a shortcut to the exit of the temple.
Go back downstairs, and go down the next set of stairs to the south.
Goron Temple B2
Go east and kill the Like Like. Then lift the boulder against the wall to reveal a hole. Go north and kill the hidden Chuchus with bombs, then find the crystal switch to the northeast. From here, use a Bombchu to go through the hole down south and hit the crystal switch in the room to the right. You have to hit the other crystal switch at the same time to make the spikes on the left go down.
After you have made the spikes go down, go west and down the stairs.
Goron Temple B3
Kill the Miniblins in this area. The pots up north will float and throw themselves at you. Go north and kill the rest of the Miniblins to make a chest appear. It contains a red rupee.
Hit the red crystal switch to turn it blue, then draw a path for a Bombchu to go through the hole and hit the crystal switch down below. You will have to hit the blue crystal switch to lower the blue blocks after the Bombchu goes past the red tiles.
After you lower the spikes, go east. Use bombs on the four Armos statues to stop them, then drag them onto the four switches.
Go past the spikes that you lowered, avoiding the pots that throw themselves at you, then go up the stairs that you find.
Goron Temple B2, part 2
Go to the left and step on the switch to create another shortcut. Then go east. You will have to fight two Hinoxes.
After defeating the Hinoxes, go up the path. You will find a crystal switch. It lowers the spikes up ahead, but only for a short time. Go north to the spikes, then use a Bombchu to hit the crystal switch, and run past the spikes before they can come back up.
To the west, there are two crystal switches across the sand. Use Bombchus to hit the two switches. Then go back to the spikes and use the boomerang to hit the crystal switch to the south. Go past where the spikes were, then go south to open the chest, which contains the Boss Key.
Take the Boss Key south, and go down the southeast stairs. Go to the left and use the Boss Key on the Boss Door, then go north, then east (the statue is telling the truth about there being no hidden doors) and go down the stairs. Follow the path from there. Read the sign to create a blue warp point. Then go through the door.
Have Gongoron try to roll next to Dongorongo's side. Dongorongo pauses briefly when it spits flames, so try to go around to Dongorongo's side then. Dongorongo sometimes charges into the wall, giving you another way to roll around to its side. When Gongoron is beside Dongorongo, tap Dongorongo repeatedly to have Gongoron bump into its side until it is knocked over. Then have Link send a Bombchu into its mouth. Switch back to Gongoron. If Link is in danger from a small enemy, switch back to Link so he can kill it. Keep having Gongoron knock Dongorongo over and having Link send a Bombchu into its mouth.
After the door opens and the bridge appears, have Link cross the bridge. Dongorongo will wake up again. When Dongorongo inhales, throw a bomb at it, then hit the blue crystal when Dongorongo falls over. Circle around Dongorongo if he spits flames, and sidestep any small fireballs that he spits. Repeat this until Dongorongo is defeated.
Open the chest to get a Heart Container, then go north into the next room. After talking to Gongoron, go north and get the pure metal, Crimsonine. Step into the blue light that appears, then go southwest to return to the Goron village. Go east and enter the Elder's house. Talk to the Elder to get 200 rupees.