Credit: Image copyright chiakto, 2014
License: CC BY-NC 3.0
Scientists have discovered more than 4,000 minerals in Earth’s crust. Some minerals are found in very large amounts. Most minerals are found in small amounts. Some are very rare. Some are common. Many minerals are useful. Modern society depends on minerals and rocks that are mined. Mining is difficult work, but is necessary for us to have the goods we use.
Image copyright chiakto, 2014. www.shutterstock.com. Used under license form Shutterstock.com.