Minerals refer to the substances, which are found naturally within the Earth and exhibits a crystalline composition.
1. Graphite can be correctly matched with a common mineral. It is a crystalline allotrope of carbon, a native element mineral, and a kind of coal. It is the most stable form of carbon under standard circumstances.
2. Ruby can be correctly matched with a gem. It is the red variety of corundum and is red due to the presence of chromium in the stone. It is a gemstone.
3. Gold can be correctly matched with a precious metal. It is a precious metal, which has been treasured since the ancient times, usually mixed with other metals to enhance its strength or change its color.