How do you get power gems in the legend of Zelda phantom hourglass?

Answer 1

there is an island not charted on the map that has a spring if you have ten power gems press a in front of the spring a voice will say wich gems do you have present select power if you have enough your power spirit will get powered up and you can equip him on the collection screen.this islan is on the bottem left on the screen and is in between three boulders and you cant see it on the map so you have to find it and then it will be charted on the map.hope this helps :>

Answer 2

Here is an extract from an IGN page.

Here is the link to the page: ign.com/wikis/the-legend-of-zelda-phantom-hourglass/Spirit_Gems

1. Buy for 500 Rupees at the Mercay Island Shop.
2. Receive from Astrid after the Temple of Fire.
3. Inside a chest in the Bomb Garden at Cannon Island.
4. Isle of Gust, on the western side of the island.
5. Inside the Temple of Wind, on the west side of the Sandworm pit.
6. Receive from Oshus after completing the Temple of Wind.
7. In a secret cavern on Mercay Island. You must have Bombs to blow open this secret cavern on the way to the Temple of the Ocean King.
8. Temple of the Ocean King, B4. Defeat all the Phantom Eyes.
9. Temple of Courage, 1F. Bomb the wall between two tablets.
10. Temple of Courage, 2F. Shoot the two eye crests for chest.
11. Temple of the Ocean King, B3. You need the Bow to shoot the eye crest on the northeast wall.
12. Goron Island, in the northern maze before the temple.
13. Isle of Frost, on a ledge in the Great Ice Field. You must first acquire the Grappling Hook to reach this ledge.
14. Temple of the Ocean King, B7. Hop on the northeast peg and activate the orb a little south.
15. Isle of the Dead, blow apart the cracked wall underground.
16. Isle of Ruins, in the northeast corner of the maze. Must first lower the water level to access this maze.
17. Molida Island, southeast of Romanos' hut. Requires the Grappling Hook.
18. Spirit Island, on the eastern side of the island. Requires the Grappling Hook to access.
19. Receive in a letter from King Mutoh after completing Mutoh's Temple.
20. Bannan Island, tiny isle to the southwest. Requires Grappling Hook.ED

Answer 3

You can find them everywhere: in treasure chests, on the sea floor, there even sold to you