"26: Behind cracked stone wall to the left of fireworks launcher: Demolish the cracked stone wall to the left of the fireworks launcher to find a red gem. You can clear away the wall even in the darkness, although it's safer to do it in light."
Just thought I'd let you know that after you've gotten this one and finish doing what you have to do in the next area where Chris's shop is and after you've gotten the next red gem, the strawberry and reached a save point. You can quit out of the game, then continue from the last checkpoint. Walk back out the gate and this same red gem quoted above will be behind the cracked wall near the fireworks again, ripe for the picking
I'm not sure if there's any other areas in the game where you are forced to backtrack and can exploit the save system to find duplicate gems but I thought I'd mention this one