Magnetite, a Real Leader

     Magnetite is a mineral that has been known about since ancient times. Magnetite is black and its crystals are usually octahedral prisms, but they can also be massive (having no distinct shape) or granular (a collection of tiny grains) Magnetite is very hard and has a dull metallic luster. Luster is a term that is used by mineralogists to describe the way that a mineral reflects light. When a mineral has a metallic luster it reflects light just like a piece of metal would. Magnetite can be found inside of volcanic bombs, which are blobs of lava that cool in midair and land on the ground solid pieces that are often a rounded shape; magnetite can also be found in meteorites. Magnetite is also known as lodestone.
     One of the most interesting properties of magnetite is that it is a natural magnet. A natural magnet is a substance that exhibits magnetism and has not been magnetized artificially like many of the magnets that we use today. Unlike many of the magnets that we use to hold things to our refrigerators, magnetite is permanently magnetized. The magnetic properties of magnetite have been known since ancient times. In fact, magnetite was said to have been discovered by a Greek shepherd who was walking over a deposit of the mineral when the iron nails in the sole of his boot kept clinging to the rock beneath him. The ancient Chinese used the mineral to make early compasses and by the twelfth century the people of Europe were doing so as well. In Europe people made compasses by tying a needle-shaped piece of magnetite to a string and letting it hand like a plum bob. They called the mineral leading stone or lodestone.
     In addition to its use as a compass needle, magnetite has served a great many uses. Magnetite is, like nearly every other mineral, a nice mineral to collect. I have even seen it in a rock and mineral kit in a toy shop. One of the most prominent uses for the mineral, however, is as an iron ore. Magnetite is about 70% iron by composition (compare that to other iron ores, such as taconite, which contains only about 17-35% iron) and therefore it can produce a great deal more iron than other ores of the same amount.
     Magnetite is found in such places as the Italian island of Elba, Siberia, South Africa, and Sweden. Magnetite makes a fine addition to any collection. A word of warning, though. Do not let a specimen of magnetite get too close to your computer or credit cards!