Diamonds belong to which crystal system as the most commonly stated classification?

Diamonds belong to which crystal system as the most commonly stated classification?

• A. Cubic
• B. Orthorhombic
• C. Trigonal
• D. Isometric or Cubic

Answer: (D)

Diamonds crystallize in the cubic (isometric) crystal system. The diamond lattice is a diamond cubic structure, based on a face-centered cubic arrangement with a two-atom basis, giving equal axes and 90-degree angles. Because isometric and cubic describe the same symmetry class, they’re used interchangeably, so this is the most commonly stated classification. Orthorhombic and trigonal describe different symmetry patterns (different axis lengths or a rhombohedral arrangement) that don’t match diamond’s high symmetry.

Diamonds crystallize in the cubic (isometric) crystal system. The diamond lattice is a diamond cubic structure, based on a face-centered cubic arrangement with a two-atom basis, giving equal axes and 90-degree angles. Because isometric and cubic describe the same symmetry class, they’re used interchangeably, so this is the most commonly stated classification. Orthorhombic and trigonal describe different symmetry patterns (different axis lengths or a rhombohedral arrangement) that don’t match diamond’s high symmetry.