When lightning strikes sand it melts, or fuses, sand particles together. The National Severe Storms Laboratory notes that when lightning hits the ground, it fuses clay and dirt into silicas, which often results in a glassy, black rock, known as a fulgurite.
Fulgurites are shaped like convoluted tubes, which leave shapes that follow the paths of lightning currents where they entered the ground. This results in fulgurites, which is a Latin word for lightning rocks. When lightning hits a tree and travels down the trunk, water below the bark converts into steam. If this steam reaches under the bark’s surface, the steam expands at a rapid rate and is able to blast out particles of bark, which often kills the wood in its path.
Lightning can benefit the Earth in a number of ways; one of the most important being that lightning is able to assist the Earth in maintaining its electrical balance. The Earth receives a recharge from thunderstorms. The atmosphere and the surface of the Earth conduct electricity readily as the atmosphere is charged positively and the Earth negatively. Without lightning and thunderstorms, the electrical balance in the Earth’s atmosphere would disappear. In addition to the above, lightning contributes to ozone-producing chemicals.