2. The first of two black minerals.This one is 8 sided, with triangular faces. Maybe it looks like some dice to you. This is magnetite, one of the few minerals to which a magnet will stick. If you have a magnet, even one on your refrigerator, see if a sample is attracted to the magnet. These magnatite specimens are from Western Australia.

Magnetite has the chemical formula of Fe²⁺Fe³⁺₂O₄. It is sometimes called lodestone.

Magentite is black, gray with brownish tint in reflected sun.

The mineral hardness scale runs from 0 to 10, and magnetite has a hardness between 5.5 and 6.5.

If you rub a piece of magnetite on a piece of white clay, you’d see that it leaves a black streak. DON’T do this without permission!

Magnetite is most found around the world, and is very common in very small amounts in igneous and metamorphic rock. It can also be found in sedimentary rock.

Magnetite is the most powerfully magnetic natural rock known. Ancient peoples discovered magnetism through working with magnetite.

Today, most magnetite is mined as iron ore.

Magnetite specimen with magnet attached.

Magnetite from New York, USA.

Magnetite

  Geologic Map of Western Australia