Force Gems are a triangular shaped gem that is formed when Link does something great for an individual. The overwhelming joy that Link brings through his actions causes a gem to be formed from the happiness. This physical form is known as a Force Gem.
Force Gems are useful because they open up new parts of the Spirit Tracks. Throughout the game there are a total of 20 Force Gems. Collecting them all will make traveling across Hyrule much easier and enable Link to collect all the Rabbits.
Force Gem 1
The first Force Gem that Link will acquire is one of the required gems needed to beat the game. After learning the Song of Birds simply play the song in Papuchia Village. Doing so will cause Link to meet with Carben. The first Force Gem is acquired by then bringing Carben back to the Ocean Sanctuary.
Force Gem 2
The second Force Gem can be received after finishing the Ocean Temple. By speaking with one of the girls in Papuchia Village you will learn that she is looking for a husband. If you go to Whittleton Village and talk to the village chief he will agree to go back with you and meet the woman. The two fall in love and their joy causes the second Force Gem to appear.
Force Gem 3
This Force Gem will also put Link in the role of helping a woman with husband troubles. Go to Castle Town and talk to the woman below the Cucoo Pen and she will let you know that her husband has gone missing. Have the woman ride along with you to the Rabbitland Rescue and they will be reunited. The third gem will be your reward.
Force Gem 4
In Aboda Village is a younger child who needs your help. He has a dream of flying so it is up to Link to make that dream reality. To make this possible Link needs to track down Beedle’s flying shop. When you enter Beedle’sfloating balloon the boy will get excited and another force gem will appear.
Force Gem 5
This Force Gem is another one of the required gems for completing the game. After you have visited Goron Village simply head to Anouki Village to find something to cool down the hot magma. Take the Anouki to the Wellspring Station and he finds that it is the perfect place to make some of his famous Mega Ice. This will cause him to get excited and a Force Gem to appear.
Force Gem 6
Now that you are able to get Mega Ice you can get this next gem. There is still some lava blocking one of the Goron’s homes. Buy more of the Mega Ice from the Wellspring Station and deliver ten units of it to the house to clear the lava and get another Gem.
Force Gem 7
In Papuchia Village there is a woman selling her supply of fish. Buy some and transport the cargo to a woman in Castle Town who is obsessed with fish. If ten units of the cargo makes it to her then you will get another Force Gem.
Force Gem 8
In Castle Town you will need to head to the Cucoo Pen that was mentioned earlier. Buy five Cucoos from the owner and bring them to Aboda Village. If you give the Cucoos to the farmer he will show his joy and a gem will appear.
Force Gem 9
The villagers in Whitteton Village are in need of some iron. They are needing to make some new axes and Iron is just what they need. If you buy some iron from the merchant in Goron Village then you can bring it back to Whittleton. The lumberjack in the village will be so thankful that a Force Gem will be produced.
Force Gem 10
The Anouki villagers are in need of some lumber. Their village is always under attack from monsters so they need a fence to keep the enemies at bay. Link will need to get lumber from Whittleton and bring it back to the Anouki. On the way there is a bridge worker that can be picked up and brought home to the village. Bringing him and the lumber back will reward you with some Rupees and another force gem.
Force Gem 11
At some point during the game Link will get a letter from Ferrus. In the parcel there is a picture and a note requesting that you pick him up. Ferrus is located to the southeast of the Snow Temple. Pick him up and take him to Aboda Village so he can meet Alfonzo, his idol. This will get another force gem to appear.
Force Gem 12
In Papuchia there is a woman known as the Wise One. Talk to her and inform her that you have been having some bad luck. She will then sell you a vessel that needs to be taken to the Snow Sanctuary. Steem will be awaiting you at the station and he will give you a Force Gem in return for the vessel.
Force Gem 13
At the station in Goron Village is a lone Goron who would like to visit the Anouki Village. Transport him to the village to get another gem.
Force Gem 14
The Anouki Honcho is dreaming of visiting someplace warm. Take him along for a ride to the Goron Village and he will express his joy causing a Force Gem to show up.
Force Gem 15
Also in Goron Village is a young Goron standing near the elder’s tent. Take him to Castle Town to get another gem.
Force Gem 16
For this Force Gem we will return to the fish merchant from earlier. So return to Papuchia Village and talk to her to find out that she needs ice to keep her fish from going bad. We will once again go to the Wellspring Station to get a load of Mega Ice to bring back to her. Ten units of the ice must survive the trip for the Force Gem to appear.
Force Gem 17
After the tracks north of the Papuchia Village have been revealed Link will be able to visit the Pirate Hideout. Enter a cave to the north of the hideout to find a Papuchia villager being held hostage. Complete the mini-game to escape with the village and return him to his home village. Doing so will reward Link with another gem.
Force Gem 18
Return to the Cuccoo merchant and buy 5 more of our feathery friends. Take the Cuccoos to Rael in the Sand Sanctuary and he will give you a Force Gem.
Force Gem 19
After completing the Sand Temple Ferrus will send you another letter. Pick him up to the northwest of the Fire Realm and transport him to the Ocean Temple to get another Force Gem.
Force Gem 20
Getting the 19th Force Gem will open up a station in the Dark Ore Mines. Before you head to the station you should first go east into a cave where you will fight against another Rocktite. After doing so head towards the Dark Ore Mine and buy some of the Dark Ore. Take the ore to the trading post through the Rocktite clear cave to avoid exposing the ore to sunlight. If you make it back to the Trading Post with at least 5 units of the Dark Ore then you will get the last Force Gem. Try using warp gates to make the trip shorter!