Magnets, Large
Hematite is the mineral form of iron oxide. It ranges in color from black to brown to red. Hematite is harder than pure iron, but much more brittle. Huge deposits of hematite are found in banded iron formations.
Grey hematite is typically found in places where there has been standing water or mineral hot springs, such as those in Yellowstone National Park. Hematite can also occur without water, usually as the result of volcanic activity.
These magnets are very powerful, so please be careful when exposing them to credit cards, cell phones, and other electronic devices!