Rubies are made from the mineral corundum or aluminum oxide. When rubies are treated to extreme heat and pressure, they are formed under the earth's surface. Corundum is made of densely packed oxygen and aluminum atoms. ... This is how the ruby is formed and gets its deep red hue.

How are rubies extracted from the earth?

A high-pressure stream of water washes the gravel away from the stream deposits. As the rocks containing the rubies are dense therefore they remain in place while the smaller deposits wash away. The gemstone is extracted by hand from these deposits as they are small and irregularly shaped.

How long does it take for rubies to form?

As the development of rubies takes 20-30 million years, tectonic movements of the earth's plates separated them into the continental shapes of today, all the while producing their ruby deposits in isolation.