Which term describes visible lines in a diamond caused by irregularities in the crystal structure?

Which term describes visible lines in a diamond caused by irregularities in the crystal structure?

• A. Graining (grain lines)
• B. Glide plane
• C. Glassie
• D. Gravity sorting

Answer: (A)

Visible lines inside a diamond caused by how the crystal grew are called graining (grain lines). Diamonds form from carbon that arranges itself into a crystal lattice, and as the crystal develops, slight variations in the lattice and growth directions create internal seams. These seams show up as thin, sometimes wavy lines that can be seen with magnification or in certain lighting. They’re intrinsic to the crystal’s structure and are not surface features. Glide plane is a crystal-symmetry concept, not a feature seen inside diamonds. Glassie isn’t a recognized term in gemology, and gravity sorting refers to a method of separating stones by density, not to internal crystal lines. So the term that best describes those visible internal lines is graining.

Visible lines inside a diamond caused by how the crystal grew are called graining (grain lines). Diamonds form from carbon that arranges itself into a crystal lattice, and as the crystal develops, slight variations in the lattice and growth directions create internal seams. These seams show up as thin, sometimes wavy lines that can be seen with magnification or in certain lighting. They’re intrinsic to the crystal’s structure and are not surface features.

Glide plane is a crystal-symmetry concept, not a feature seen inside diamonds. Glassie isn’t a recognized term in gemology, and gravity sorting refers to a method of separating stones by density, not to internal crystal lines. So the term that best describes those visible internal lines is graining.