The Pyramid Jewel is a quest item from The Legend of Zelda: Oracle of Seasons. This red jewel can be found by diving into the water northeast of Dancing Dragon Dungeon. This jewel, along with the Square Jewel, Round Jewel, and X-Shaped Jewel, is required to gain access to the Tarm Ruins.
In a Linked Game, the jewel is found in a chest in the underwater cave in Sunken City at coordinate 7, O. There, after opening the chest, Link is taunted by Vire, who moves the Pyramid Jewel onto a higher ledge. After this, Link must retrieve the Pyramid Jewel by diving into the cave from Sunken City.
Although it is not required, the Treasure Map is helpful in finding the Pyramid Jewel.