01
What to look for
Under 10x loupe: curved or wavy lines of tiny dots forming patterns that look like a human fingerprint. They occupy flat planes within the stone, and the dots are micro-bubbles or fluids trapped in a healed fracture.
02
What it means
Fingerprint inclusions support natural origin and are common in many natural gemstones. Their shape and orientation can also point toward gem species or growth conditions.
03
Expert move
Look at the edge of the fingerprint inclusion: the tiny dots are fluid micro-inclusions. This differs from growth zoning, which forms straighter or more systematic lines.