What is the primary composition of diamond?

Diamonds are primarily composed of carbon atoms. In the structure of a diamond, each carbon atom is bonded to four other carbon atoms in a three-dimensional arrangement. This strong covalent bonding imparts diamonds their renowned hardness and brilliance. The unique arrangement and bonding of the carbon atoms contribute to the gem's optical properties, making diamonds highly valued not just for their physical characteristics but also for their aesthetic appeal in jewelry.

Silicon, oxygen, and hydrogen do not form the crystalline structure of diamond. While silicon is a significant element in various minerals and compounds, including some that are present in different gemstones, it is not the fundamental building block of diamonds. Oxygen and hydrogen are also not components of diamond's structure, as they do not participate in the formation of its crystalline lattice. This clear definition of diamonds as a form of elemental carbon allows for a deeper understanding of their properties and classifications within the realm of gemstones.