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Minerals

Scientists have identified more than 2,500 different
minerals. Minerals are natural, nonliving substances made up of
particles that are arranged in regular patterns. They are the
building blocks of rocks. Minerals include salt, talc, metal ores,
and gemstones. Some rocks consist of only two minerals, while
others are made up of dozens. Minerals give rocks their basic
qualities - color, hardness, texture, density, and luster. (Luster
means that the rock looks metallic, or glassy, or pearly, and so on).
As magma cools, chemicals in the magma form minerals.
As igneous rocks change into metamorphic rocks, the minerals
change, too, into new forms of minerals. Some minerals are
dissolved in underground water. Over time, these minerals grow
into crystals.
When many minerals are concentrated in the same area,
they can be mined.

Comprehension Questions

I. Say which of the following statements are false and
which are true. Correct the false statements to make them
true.

1. Scientists have identified more than 20,500 different
minerals.
2. Minerals are the building blocks of rocks.
3. All rocks consist of dozen minerals.
4. Chemicals in the cool magma form minerals.
5. Many minerals concentrated in the same area can be
mined.

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