This is a herobrine, the one that is flying. He is a boss and he has powers that can destroy everyone and anything. He can fly and pick blocks up and throw them at you like in this photo.
These are diamonds. Diamonds are the rarest items in minecraft and they can make a sword, a pickaxe, an axe, a shovel and that is all the tools you can make with them, but you can make armour and you can do a a helmit, a chestplate, pants and boots.
