'GHOST APPLES' : These really look as if they are made of crystal!
A man pruning apple trees in an icy orchard in Michigan discovered a very odd phenomenon 'ghost apples'. A freezing rain coated the rotting apples, creating a solid icy shell around them. As he pruned the trees, the trees shook, causing some apples to fall off. But those that remained on the tree had the mush slip out the bottom, leaving 'ghost apple'.
Ghost apples are so rare because they require very specific weather conditions - where it is cold enough for water to freeze but also to allow the apples inside the casing to rot.