Bruce Dorcy, age 9, Seattle, Wash., for his question:
What is graphite?
Sometimes Mother Nature seams extravagant to the point of wastefulness. A trillion spores are launched that one may grow into a mushroom. Countless insects are born to be gobbled up by hungry birds and frogs. Only one or two out of a great many may live to lay eggs that will survive the winter, lend, after every summer, myriad leaves and tons of old lumber fall to rot in the ground.
When we learn more we see that those things are not wasteful. Actually Mother Nature is a very neat and economical housekeeper. Her apparent waste is always part of a large and orderly plan. Insects feed birds and frogs and they, in turn, feed larger animals. In that way our world remains populated with a multitude of fascinating creatures.
As to natures s Plant Kingdom, not one fallen leaf is wasted. Bacteria garbage men in the soil break up the old vegetation into basic chemicals. These chemicals provide food for new generations of plant life. When there are no garbage men bacteria, nature stores and presses her old vegetation in the ground. Down there it changes bit by bit from debris into precious coal.
Our coal was made from the garbage of ancient swamp forests. The garbage men bacteria could not hive in the stagnant waters. Leaves and lumber fell and could not decay. Great lagers of forest garbage were covered with new soil. Cases and light materials escaped from the debris. The layer of soggy vegetation became a kind of peat.
Time passed and the peat changed into brown, low‑grade coal called lignite. By now, 65% of the remaining debris was carbon. More materials escaped or were driven from the lignite. In time, 88% of the coal was carbon. It was now shiny black bituminous coal. In some regions this soft coal was pressed between bending folds of the earth’s crust. It became hard, or anthracite, coal, 901~c of which is carbon.
The buried coal goes on changing until only pure carbon remains. When this happens it has become a layer of graphite. This soft, black mineral has lost its usefulness as a fuel. For graphite withstands terrific temperatures without burning. Then, after all these eons of time, is this waste material? Not at all.
The lead in a pencil is made of Graphite. The soft, black mineral is composed of small carbon crystals that tend to rub off on a rough surface. It is smooth and slippery to touch. Mixed with reuse it protects shiny metal and is useful as a lubricant to keep the wheals of industry running smoothly.
Graphite has a job in foundries and furnaces, though not as a fuel. It is used to line the molds which receive molten metal as it makes a smooth surface and will not burn at high temperatures. It is also a good conductor and is used in electrical equipment. Powdered graphite is used in certain paints. Old Mother Nature, it seems, does not waste so much as a twig or a fallen leaf.