Green Joy Ring
"Find double Ore Chunks"
In Oracle of Seasons, go to the Sunken City and change the season to Summer. Use the hidden underwater pathway to get to Mt. Cucco. Walk up and right a screen and use the Tree Stump to change the season to Spring. Walk to the right a screen and then up a screen to find the Flying Cucco. Grab it with the Power Bracelet and repeatedly tap the button to fly up to the highest platform. Drop down and enter the Cave found here. Use the moving platform to reach the floor switch, causing a Seed Ring to appear. Use the moving platform to grab the Seed Ring, which becomes the Green Joy Ring when appraised.
When equipped, the Green Joy Ring will double the value of every Ore Chunk that is collected. Ore Chunks are collected in Subrosia and they are the primary form of currency. The Green Joy Ring works well in collected ore chunks in a short period of time.
There are similar rings in form of the Red Joy Ring that effects Rupees and the Blue Joy Ring, which effects Recovery Hearts. However, all these Rings become obsolete in comparison to the Gold Joy Ring, which carries all the attributes of the Red, Blue, and Green Joy Rings, plus more.