What if I told you that your precious ruby stone was just an impure, transparent mineral?
This mineral is one of the naturally transparent minerals, but can be different colours when impurities are present, making them ruby red or sapphire green.
Corundum is so hard that it can scratch almost any other mineral, meaning it is commonly used in large machines used in machining metals, plastics and wood.
Corundum is also unusually dense, which is rare for a transparent mineral composed of low atomic mass elements.
Corundum is also used as an abrasive and is mined in Zimbabwe, Russia, Sri Lanka and India.
It is also synthetically manufactured to be used for this purpose.
