Which crystal form is described as having eight equal triangular faces?

Which crystal form is described as having eight equal triangular faces?

• A. Near-gem
• B. Old European cut
• C. Octahedron
• D. Open-pit mining

Answer: (C)

A crystal form describes the natural shape of a mineral, and eight equal triangular faces point to an octahedron. A regular octahedron is like two square pyramids joined at their bases, giving eight congruent triangular faces. In diamonds, the octahedral form is a classic natural shape due to the cube-based crystal system. The other terms refer to human-made diamond cuts or mining methods, so they don’t describe the crystal’s natural geometry.

A crystal form describes the natural shape of a mineral, and eight equal triangular faces point to an octahedron. A regular octahedron is like two square pyramids joined at their bases, giving eight congruent triangular faces. In diamonds, the octahedral form is a classic natural shape due to the cube-based crystal system. The other terms refer to human-made diamond cuts or mining methods, so they don’t describe the crystal’s natural geometry.