Magnetite's color ranges from a reddish to a brownish black. It is an opaque mineral and has a somewhat metallic shine to it. Its crystalline formation is octahedral and within that, it usually reveals either triangular- or square-shaped regions. It mostly looks black, but its metallic luster offsets the deep tone of the mineral.
The mineral's primary property is its strong magnetic quality. This was useful to the ancient Chinese who used the material to make the very first compasses, which relied on magnetism. On the Mohs Scale used for measuring hardness it registers between 5.5 to 6.5, which is quite hard. Fe3O4 is its chemical formula and its chemical name is ferrous-ferric oxide. It is essentially an iron ore, and when it reacts with oxygen, it is capable of producing another iron ore called hematite.
Magnetite is found worldwide. You can find it in both igneous and metamorphic rocks and even sometimes in sedimentary rocks, so it is quite common. Very big deposits of the mineral are located in Kiruna in Sweden and the Adirondacks in New York. The region called Pilbara in Australia also contains large deposits, while smaller ones are found in Europe, Africa and both North and South America.
Because of its nature, you can separate magnetite quite readily from any soil in which it exists by using a simple hand magnet. Since it is essentially magnetic iron ore, it will separate from any other nonmagnetic material around it. Scientists have also observed that a type of bacteria, which are called magnetotropic, can create magnetite under certain conditions.