Inclusions can indicate where a diamond formed within the earth.

• A. Where it formed
• B. What color
• C. Location of formation
• D. Its age

Answer: (C)

Inclusions are actual minerals trapped inside a diamond as it crystallizes, preserving a snapshot of the environment at the moment of growth. Because those trapped minerals form only under specific pressure–temperature conditions and in particular geologic settings, they reveal the depth and region where the diamond formed. Identifying the inclusion minerals and their textures helps determine whether the diamond formed deep in the mantle or in a crustal setting, i.e., its location of formation. In contrast, color is mainly about impurities in the diamond lattice, and age isn’t directly inferred from inclusions in routine gemology.