[Daily Science] Overview of Natural Diamond
Release time:
2026-06-25
In general, the quality of industrial natural diamonds is evaluated based on the following aspects:
(1) Crystal shape: Octahedral and dodecahedral shapes are preferred, with a predominance of dodecahedrons being particularly desirable. Other forms—such as incomplete crystals, agglomerates, or intergrown crystals—are considered inferior;
(2) Internal structural defects: Quality improves as internal defects (such as cracks, inclusions, and spots) decrease or are absent;
(3) Transparency: Higher transparency indicates better quality; colorless, brilliant, and lustrous stones are preferred, whereas dull, yellow, or dark gray stones are considered inferior;
(4) Surface condition: A smooth, intact surface free of fissures or sharp protrusions is preferred
