Which term describes a small, concentrated area of crystal distortion that can appear white or dark and may be thread-like or pinpoint-like?

Which term describes a small, concentrated area of crystal distortion that can appear white or dark and may be thread-like or pinpoint-like?

• A. Gravity sorting
• B. Grain Center (GrCnt)
• C. Grease belt
• D. Graining (grain lines)

Answer: (B)

Graining describes internal growth irregularities in a diamond’s crystal lattice. These tiny distortions show up as small, localized areas that can appear white or dark and may look thread-like or pinpoint-like when viewed with magnification. They arise from how the crystal grew and the varying directions of lattice alignment, creating visible lines or patches inside the stone. This directly matches the description of a small concentrated area of distortion that can appear white or dark and may be thread-like or pinpoint-like. Gravity sorting, Grease belt, and Grain center don’t describe internal crystal distortions. Gravity sorting is a processing term about density separation, the grease belt is unrelated to diamond internal features, and grain center would refer to a location within a grain rather than a visual distortion pattern. Thus, the term that best fits is graining (grain lines).

Graining describes internal growth irregularities in a diamond’s crystal lattice. These tiny distortions show up as small, localized areas that can appear white or dark and may look thread-like or pinpoint-like when viewed with magnification. They arise from how the crystal grew and the varying directions of lattice alignment, creating visible lines or patches inside the stone. This directly matches the description of a small concentrated area of distortion that can appear white or dark and may be thread-like or pinpoint-like.

Gravity sorting, Grease belt, and Grain center don’t describe internal crystal distortions. Gravity sorting is a processing term about density separation, the grease belt is unrelated to diamond internal features, and grain center would refer to a location within a grain rather than a visual distortion pattern. Thus, the term that best fits is graining (grain lines).