What is the primary component of a diamond?

The primary component of a diamond is carbon. Diamonds are a crystalline form of carbon, where each carbon atom is bonded to four other carbon atoms in a tetrahedral structure. This unique arrangement of atoms gives diamonds their exceptional hardness and brilliance, making them highly sought after in jewelry and industrial applications. The physical and optical properties of diamonds stem from the nature of these carbon-carbon bonds, which contribute to their strength and clarity.

In contrast, the other options represent elements that do not form the structure of a diamond; oxygen is not a component in its structure, silicon is a different element that forms various minerals but not diamonds, and iron is a metal that does not contribute to the crystal lattice of diamonds. Thus, understanding that diamonds are specifically composed of carbon is key to recognizing their unique properties and significance.