All treasure chests can be opened again after you play the Song of Time. Except for the one in the treasure chest shop, all treasure chests you already opened stay opened until you play the Song of Time. Except for heart pieces and masks, treasure chests that have an item you already have will give you a blue rupee when you open them. All treasure chests that have a heart piece or mask that you already have will give you a recovery heart when you open it. You also get a blue rupee when you open a chest with an item you can't get. For example, since you can't carry any bombchus without a bomb bag, if you open a treasure chest that has bombchus when you don't have a bomb bag, you get a blue rupee. Any fire ring around a treasure chest will disappear after you get what was in it from clipping through the fire and opening the chest. Stray fairies aren't always gotten right away after you open the treasure chest it was in so if there was a fire ring around that treasure chest, the fire ring disappears when you get the stray fairy, not when you open the treasure chest.