You can access the Dark Ore Mine after carrying Ferrus from the Fire Realm to the Ocean Temple after getting his letter.
But before that, you first have to carry Ferrus from the Snow Realm to Aboda Village. Did you do that part?
Once Ferrus is in the Ocean Temple, he'll give you a Force Gem, that will energize tracks leading toward the twisted tunnels. Not too far down, you'll find the Dark Ore Mine, selling 10 units of Dark Ore for 200 rupees.
To get the Ore to Linebeck, go here:
http://www.zeldadungeon.net/Zelda13-spirit-tracks-walkthrough-11.php
It's about a third down the page.
First you need to finish the side quests from Ferrus.
-He will ask you to pick him up somewhere in the Fire Realm (N-W)
-Bring him to the Ocean Realm (Like he asked)
-He'll give you a Force Gem which unlocks new train rails in the Fire Realm in the east
-Now go to the new train rail and there will be a station on the horizontal section of the newly unlocked rail
-Go to the centre entrance of the station and go straight until you meet a Goron
-Talk to the Goron
-Buy Dark Ore for 200 Rupees (WARNING! Before buying the Dark Ore, it is better to defeat the cave monster first. Like...Really deafeat until he dies.)
-After buying the Dark Ore, go down into the Sand Realm
-Use the teleport to the west side of the realm
-Then go to the teleport which brings you to the Ocean Realm kinda...
-Take the teleport right under you (on the map) which brings you to the Forest Realm
-Now drive to the Trading Post
Now you should have about 7 or 6 Dark Ore left which will make Linebeck very happy and he'll give you the Force Gem for the Lost thigny thing Station in the Ocean Realm ^^
You must obtain the compass of light at the altar at the top of the tower of spirits. You know the two eyeballs at the top of the tower? If you do, take out your bow of light and hit them with an arrow. Wow! An altar will appear!
You can find a Dark Pearl Loop if you look in different treasure chests.
in the snow realm
It is in the fire realm the Northeastern part of the map. You get there from the Snow realm
it isnt on the island but they are gazing diagonally
You say no to all of her questions.
No. There is no underworld in Spirit Tracks. But i guess the cloest thing to it would be the Dark Realm you go to kill the final boss.
No Idea what you're talking about there are lots of puzzles
after talking to that important goron in the fire realm. they want you to bring them something cold.
Try the Trading Post. South-east end of Forest Realm.
if you want a force gem
you find him in the snow realm when you defeat the crab monster in the cave to lead to the sand sanctuary.
At the Bridge Builder's house, in south western snow realm.
i was stuck on dat as well.wat u draw is 2 diamonds beside each other.dat is it. ! /