Kinstone

are items in. They are mystical green, red, blue, and gold medallions that can yield Rupees and Pieces of Heart, and on several occurrences, begin sidequest events when two Kinstone pieces of identical color and shape are fused. These Kinstones, created and hidden about Hyrule by the Minish, are seen as a sign of immense happiness, especially if two people are engaged in Kinstone Fusion.

Types and Function
Green Kinstones are found in abundance across the overworld; they can be found by opening Treasure Chests, cutting grass, digging, or defeating enemies. This Kinstone commonly yields a Rupee reward when fused. The Goron Merchant sells Green Kinstones for 50 Rupees at his stall in Hyrule Town.

Blue Kinstones are uncommon, even though they can be obtained much like Green Kinstones, in that simply opening Treasure Chests, cutting grass, digging, or defeating enemies will likely reveal them. Blue Kinstones are most notable for their role in fusing to the Mysterious Walls hidden within the caves of Hyrule, aiding in the completion of the Goron Sidequest. The Goron Merchant sells Blue Kinstones for 200 Rupees.

Red Kinstones are rarer than Blue Kinstones; they can only be bought or claimed from Treasure Chests. Only if the White Picolyte is used, Red Kinstones can be revealed by cutting grass. The fusion of a Red Kinstone often yields a gratifying reward, such as a Piece of Heart, 50 or more Rupees, or the opening of previously inaccessible passageways through waterfalls, tree trunks, and cave walls. Sometimes the fusing of a Red Kinstone yields a Treasure Chest that contains another Red Kinstone. The Goron Merchant sells Red Kinstones for 300 Rupees.

Gold Kinstones are the rarest Kinstones and the only type that cannot be found in the overworld or bought. Only ten of them can be found in the game. They are only discovered and used as a function of the plot. Castor Wilds, Cloud Tops, and Veil Falls are the only regions that incorporate these Kinstones, used to open various passageways necessary for Link to continue his journey. These Kinstones cannot be fused with a Kinstone from another character like the others.

Kinstone Bag
The Kinstone Bag is a item that carries Kinstones. It is received in Hyrule Castle Town after the completion of the Deepwood Shrine. Over the course of the game, the bag will grow and bulge as Link collects more Kinstone pieces. However, the bag has an infinite Kinstone carrying capacity. The Kinstone Bag will be turned into a Tingle Trophy by the TMC: after Link fuses Kinstones with all one hundred Kinstone-holding characters in the game.