Patricia Moore, age 15, of Redwood City, Calif., For her question:

What is magnetic ore?

Several minerals have some faint magnetic properties, but sooty black magnetite Often has all the properties of a strong magnet. Two small samples of magnetite have enough magnetic pull to attract each other and cling together. Some samples of magnetite have north and south magnetic poles. They are natural lodestones, and a sliver of this strongly magnetized mineral can be used to make a magnetic compass.

Magnetite is rich in iron, and plentiful deposits often are used as ore from which iron is extracted. It is a magnetic ore of iron. There is no shortage of magnetite in the earth's crust. Rich deposits exist in New England and other eastern states. There is more magnetite in Utah and still more in California.